This PDF file contains the front matter associated with SPIE Proceedings Volume 10250, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.

This article is in connection with calculating of reflection critical angle on interface, author has found that reflective wave have a quarter wavelength effects and deduced both absolute and relative reflection critical Angle calculation formulas. The two formulas can easy solve the question of reflection critical angle on interface of one side of the air where it is not calculated by Snell’s law. Snell’s law only reveals that rate of the wave velocity projected to the interface, the methods of this paper reveal the normal component of wave velocity on the interface relationship. The methods will be widely used in various fields such as light, electromagnetic waves, sound waves and water waves etc.

Using the transfer matrix method for analyzing the chirped fiber Bragg gratings reflective spectrum and group delay ripple. Compared the difference in reflective spectrum and group delay ripple(GDR) among unapodized chirped fiber Bragg gratings, symmetrical apodized chirped fiber Bragg gratings and asymmetrical apodized chirped fiber Bragg gratings. The grating is divided into three segments, we focus on how to select an optimal parameters ‘a’ in Gaussian profile of each segment by comparing the change of full width half maximum(FWHM) and the change of mean group delay ripple between unapodized chirped fiber Bragg gratings and partly-apodized chirped fiber Bragg gratings.

Multilayer defects which reside on the top or inside the multilayer are one of the most critical concerns in the extreme ultraviolet lithography (EUVL) manufacturing process. We proposed the transport of intensity equation and partial least-square regression (TIE & PLSR) method to inspect the defect and reconstruct its geometric parameters: height and full width at half maximum (FWHM). The transport of intensity equation (TIE) is employed to retrieve the phase of the multilayer defect from the two scattering images, which collected at two adjacent propagation distances. Comparing the simulated ideal phase, the phase deformations caused by different top heights and widths of the defects are analyzed. The optical properties maximum, minimum and fitting Zernike coefficients are used to parameterize the phase deformation. Partial least-squares regression (PLSR) is applied to associate the optical properties of the phase deformation with the geometric parameters of the defects, and reconstruct geometric parameters of the measured defect from the established data library. The reconstruction error is less than 0.2% in simulation experiment.

At present, there are various methods to compute the infrared radiation characteristics of exhaust plume of the liquid rocket engine. Though they are different in computational complexity. Their ideas and methods are alike. This paper focuses on the computation methods of exhaust plume’s flow field, spectral parameters and radiation transfer equation. Comparison, analysis and conclusion of these methods are presented. Furthermore, existing problems and improvements of them are proposed as well.

In this paper, we propose the index matched anisotropic crystal lens. The proposed optical element acts as a transparent glass in extraordinary polarized light and a lens in ordinary polarized light. The conceptual diagram and principle of the index matched anisotropic crystal lens are presented and the ray tracing simulation is performed to verify and analyze the functionality and the distortion of the real world scene. The index matched anisotropic crystal lens is implemented with calcite and the index matching liquid. The preliminary system to show the feasibility of the proposed optical element is implemented. The lens mode and the transparent mode are presented and the distortion along the incident direction of the light is also analyzed by the experiment. It is expected that the index matched anisotropic crystal lens can be a good candidate for the head-up display and head-mounted display.

Human retina is different from other ocular tissues, such as cornea, crystalline lens and vitreous because of high scattering performance. As an anisotropic tissue, we cannot neglect its impact on the polarization state of the scattered light. In this paper, Mie scattering and radiative transfer theory are applied to analyze the polarization state of backscattered light from four types of retinal tissues, including neural retina, retinal pigment epithelial (RPE), choroid and sclera. The results show that the most backscattered zones in different depths have almost the same electrical fields of Jones vector, which represents the polarization state of light, whether neural retina layer is under normal incidence or oblique incidence. Very little change occurs in the polarization of backscattered light compared to that of the incident light. Polarization distribution of backward scattered light from neural retina layer doesn’t make apparent effects on polarization phase shifting in spectral domain OCT because its thickness is far less than photon mean free path, while other retinal tissues do not meet this rule.

The performance of optical systems is obviously affected by the surface defects of optical components in terms of losses and image degradation. In this paper, the feasibility of characterizing surface defects of Silicon substrates was investigated by the total scattering (TS) and absorption. The TS values of three Si substrates with different surface finish level were obtained by using the total scattering measurements at wavelength of 633nm. The surface roughness was analyzed by the atomic-force microscope (AFM) and the number of 1μm diam defects in a beam spot was recorded by the optical microscope. Additionally, the scattering value of 1μm diam defects was determined by the ratio of the different value between TS value and the scattering value induced by roughness to the number of the defects in a beam spot. Furthermore, based on the Mie scattering theory, the theoretical value was calculated and was compared with the measured results. The results show that both the theoretical and measured results have the same order of magnitudes. What’s more, in order to study the absorption, the absorption of four samples that include three Si substrates with different finish level and one Si substrate with a high reflector coating were measured by using the surface thermal lensing technique. The experimental results reveal that the poorer the finish level is, the more the number of surface defects is. Finally, the absorptance mapping of the high reflector was plotted and compared with the results observed by the optical microscope and the results indicate that the absorption measurement is an effective method to characterize the surface defects of Si substrates.

We build numerical models of dual-waveguide trap with rough and tilted endfaces using both the finite element method. The optical field distribution of waveguide trapping house with rough and tilt endfaces is simulated and analyzed. The results shows that rough endfaces cause the incident beam scattered and the tilted endfaces make incident beam refracted. According to optical field distribution, axial and transversal optical trapping forces are calculated. When endfaces roughness increase, both the axial and transversal trapping forces decrease, meaning trapping depth decreased. The transversal equilibrium positions move around unpredictably, off center. The stiffness and width of optical trap change little. When endfaces tilt angles increase, both the axial and transversal trapping forces decrease, meaning trapping depth decreased. The transversal equilibrium positions move along minus transversal axis. It is no obvious change in stiffness and width of optical trap.

Stitching interferometry is an effective method to extend the measurement range of commercial interferometer. It has been applied in the laboratorial environment, but rarely in workshop. In order to improve the testing efficiency in workshop, stitching interferometry could be combined with machine tool and implement in-situ testing. A dynamic stitching interferometer system is established in this paper, which contains dynamic interferometry, precision motion control and advanced stitching algorithm. This system has been prepared for the in-situ testing of large plano optics. One example optical flat with size 200mm×300mm was used to verify the feasibility and accuracy of this system. Many repetitive experiments have been proved the well reliability of the system and method.

The radial smoothing scheme based on optical Kerr effect was proposed to quickly improve the irradiance uniformity of the laser beam. In order to analyze the moving characteristics of speckles on target plane, the transverse moving model has been established based on the concept of equivalent focal length. The analytical expression for the radial moving speed of the speckles in radial smoothing (RS) has been derived, and the moving characteristics have further been analyzed. Results indicate that, the focal spot tends to be larger when the radial moving speed increases. With a temporal shape of triangular wave, the pump laser generates a constant radial moving speed and achieves better smoothing effect. Due to the difficulty in obtaining the triangular pump laser in picoseconds level, the temporal shape of Gaussian wave was further optimized to obtain the greater speed while maintaining the same beam smoothing performance in the RS scheme. To further improve the smoothing performance of the radial smoothing scheme, the hybrid dispersion grating scheme is introduced to achieve the multidirectional smoothing. By introducing the hybrid dispersion grating to the radial smoothing scheme, the final beam smoothing performance is much better than either of them.

This paper investigates the aperture-averaged angle-of-arrival variance for a Gaussian wave propagating through the weak anisotropic non-Kolmogorov atmospheric turbulence along a horizontal path. A heuristic model is deduced from the results of plane and spherical waves under the geometrical optics approximation. The mathematical expression include the spectral power law value, the anisotropic factor and other essential optical parameters of a Gaussian wave.

We present a Monte Carlo static light migration model (Endo-MCML) to simulate endoscopic optical spectroscopy for tubular organs such as esophagus and colon. The model employs multi-layered hollow cylinder which emitting and receiving light both from the inner boundary to meet the conditions of endoscopy. Inhomogeneous sphere can be added in tissue layers to model cancer or other abnormal changes. The 3D light distribution and exit angle would be recorded as results. The accuracy of the model has been verified by Multi-layered Monte Carlo(MCML) method and NIRFAST. This model can be used for the forward modeling of light transport during endoscopically diffuse optical spectroscopy, light scattering spectroscopy, reflectance spectroscopy and other static optical detection or imaging technologies.

We proposed a new structure of highly nonlinear low- dispersion photonic crystal fiber. Numerical results show that the dispersion variation is within ± 0.7 ps·km^-1·nm^-1 in the C band, and the corresponding nonlinear coefficient is 60.5 60.5 W^-1·km^-1. With the 6 W peak power of the input pulse, and PCF with 800 m length generates a SC with a spectrum ranging from 1500 to 1800 nm.

In order to analyze the character of light and system, the polarization states of transmitted light through the liquid crystal spectropolarimetric system are investigated in the different modulation cases. After the Mueller matrix of system is obtained based Stokes vector and Mueller matrix theory, the distribution of the polarization states of incident light is drawn down in a ball with varied modulations of different rotatory angle, different areas and different phase delay. The reached conclusion is that the incident light is changed from completely polarized light to partially polarized light through system, which is clustered together around 45° in x-y plane and turned into linearly polarized light. Gathering together is mainly caused by tunable filter and varied modulation types lead to different gathering positions around 45°. By investigating the polarization states of transmitted light through the liquid crystal spectropolarimetric system, the change rules of polarization states are obtained which can lay the foundation for system optimization and light properties analyzing.

CTR (Current transfer ratio) is generally used to characterize the reliability parameters of optocoupler in engineering. However, high-speed optocoupler has a different structure from the common optocoupler, therefore its most important parameter should be propagation delay time. In addition, CTR serving as the macroscopic parameters, its changes can’t directly reflect microscopic changes of the internal defects in device. It is discovered that the number of microscopic defects in the device and the level of low-frequency noise shows a positive correlation. In terms of high-speed optocoupler, this paper proposed a method of combining propagation delay time and low-frequency noise to evaluate the storage reliability.

The paper demonstrated how to design circuit to test these parameters and obtain their variations trajectory in accelerated degradation test. In this paper, 20 VO2630 devices were divided into four groups, and a accelerated test at 100°C, 125°C, 150°C and 175°C was conducted to monitor propagation delay time and other parameters related with low-frequency noise. These parameters had different degrees of degradation. This paper showed the degradation process of propagation delay time. It was found that the initial value of propagation delay time was nearly identical, but parameters related with low-frequency noise had different initial values. The larger the initial value of low frequency noise is, the faster propagation delay time will degrade. The main cause of degradation of propagation delay time is Schottky clamped transistor degradation. Finally, this paper discussed the advantages and disadvantages about utilizing conventional electrical parameters or low frequency noise to evaluate the reliability.

In order to improve the remote target detection ability of infrared (IR) images effectively, an infrared telephoto objective for 3μm~5μm and 8μm~12μm dual wave-band is designed for 640 pixel×512 pixel infrared CCD detector. The effects of the surrounding environmental temperature are analyzed and the refractive diffractive hybrid thermal compensation is discussed. The focal length of the system is 200mm, the relative aperture is 1:2.2 and the field of view is 7°. The infrared dual band telephoto system with small volume and compact structure is designed in a large range of temperature. The system is composed of four lenses with only three materials of zinc sulfide, zinc selenide and germanium to compensate for the temperature. The image quality of the system is evaluated by ZEMAX optical design software. The results show that the modulation transfer function (MTF) for each field of view at cut-off frequency of 17 lp/mm are respectively greater than 0.6 and 0.4 which approaches the diffraction limit. The telephoto objective has favorable performance at the working temperature of -40°C~+60°C. The relative aperture, field of view, and focal length are same for both spectral regions. The system meets the requirements of technical specification.

By fusing the visible and infrared images to improve the detection and recognition ability of equipments is a focus research. Aiming at the contradictory aspects of the current fusion algorithm for speed and accuracy, a fusion algorithm of visible and infrared images is proposed. Firstly, the visible and infrared imaging systems’ calibration information is obtained by calibrating the system. Secondly, the correspondence between visible image and infrared image pixel is established through constructing mathematical model. Finally, on the basis of Laplace decomposition, the visible and infrared images is fused with regional energy optimization principle. The experimental result shows that the proposed method increases the speed by 22.9%, improving the real-time performance of the fusion algorithms, while remains registration accuracy unchanged.

As a new imaging mechanism, ghost imaging has become a hot area of research in optical imaging field. In this paper, the effect of intensity correlation order on lensless ghost imaging system is investigated. We demonstrate that the image quality of Nth-order ghost imaging and Nth-order ghost imaging with background subtraction can be affected by the different intensity correlation order of test light and reference both theoretically and experimentally. The result indicates that the image quality will not be certainly increased with the increasing of the intensity correlation order, and here will be very useful for choosing an appropriate intensity correlation order in practice.

The non-uniformity response in infrared focal plane array (IRFPA) detectors has a bad effect on images with fixed pattern noise. At present, it is common to use shutter to prevent from radiation of target and to update the parameters of non-uniformity correction in the infrared imaging system. The use of shutter causes „freezing‟ image. And inevitably, there exists the problems of the instability and reliability of system, power consumption, and concealment of infrared detection. In this paper, we present an efficient shutter-less non-uniformity correction (NUC) method for infrared focal plane arrays. The infrared imaging system can use the data gaining in thermostat to calculate the incident infrared radiation by shell real-timely. And the primary output of detector except the shell radiation can be corrected by the gain coefficient. This method has been tested in real infrared imaging system, reaching high correction level, reducing fixed pattern noise, adapting wide temperature range.

This paper proposes a finite adaptive neighborhood suppression algorithm based on singular value decomposition for small target detection in the infrared imaging system. The algorithm firstly does singular value decomposition on the whole gray image, selecting the larger singular values to reconstruct the image and achieving the purpose of noise suppression, thereby obtaining the image matrix contains only weak point of the target and its possible. Then, the pixels are divided into foreground and background in the fixed neighborhood followed by contrast enhancement. Experimental results show that this method can effectively preserve image details and the inhibiting effect is better.

An effective total variation-based nonuniformity correction (NUC) is presented to remove the nonuniformity in infrared focal plane array in this paper. In this method, we treat the NUC problem as an ill-posed inverse problem and set L1-norm horizontal total variation regularization (L1-HTV) to solve. By a more realistic geometrical consideration on the nonuniform noise, the L1-HTV regularization only constrains the gradients along the x-axis in space domain and time domain while protects the gradients along the y-axis. As a result, nonuniformity can perfectly removed effectively, while the details and edges are well preserved. In addition, we use the Split Bregman iteration to minimize the regularization term in the model, which highly reduces the computational complexity so that it can be used in real-time video sequence. We test the experiments on real scene under different circumstances and indicate that our algorithm is effective and efficient.

This paper presents a synchronous multipoint velocity profile measurement system, which acquires the vibration velocities as well as images of vibrating objects by combining optical heterodyne interferometry and a high-speed CMOS-DVR camera. The high-speed CMOS-DVR camera records a sequence of images of the vibrating object. Then, by extracting and processing multiple pixels at the same time, a digital demodulation technique is implemented to simultaneously acquire the vibrating velocity of the target from the recorded sequences of images. This method is validated with an experiment. A piezoelectric ceramic plate with standard vibration characteristics is used as the vibrating target, which is driven by a standard sinusoidal signal.

Working all-day and all-weather, the passive millimeter wave radiometer is widely used in remote sensing, guidance and other fields. In order to solve the increasingly serious problem of water pollution, especially the pollution caused by the rapidly breed of the aquatic plants, a simple and effective method to monitor the water environment is proposed. Aquatic plants can be distinguished through millimeter wave system, as they have high bright temperature compared to Water. The 8mm radiometer is used to measure the radiation characteristics of aquatic plants and image. The simulation results and radiation imaging experiments prove the feasibility and effectively of monitoring aquatic plants by millimeter wave radiometer. This study will contribute to monitoring the aquatic plants growth and decreasing the pollution.

In order to figure out how changes in equipment and environment impact the imaging result and find out a best imaging condition, in this paper, microbubbles with micron diameter is detected and imaged through a simulated supercavity layer in laboratory. After the image processing, the result shows the changes in distance of bubble region affect the imaging little. When the detection angle is 90 degrees, the bubbles have the clearest imaging. And the growth of bubble number in imaging is increasing with current and reaching saturation at a constant value, and the smaller the diameter of bubble is, the higher sensitivity towards current has.

Detailed imaging and analysis of skin structures are becoming increasingly important in modern healthcare and clinic diagnosis. Nanometer resolution imaging techniques such as SEM and AFM can cause harmful damage to the sample and cannot measure the whole skin structure from the very surface through epidermis, dermis to subcutaneous. Conventional optical microscopy has the highest imaging efficiency, flexibility in onsite applications and lowest cost in manufacturing and usage, but its image resolution is too low to be accepted for biomedical analysis. Infrared parameter indirect microscopic imaging (PIMI) uses an infrared laser as the light source due to its high transmission in skins. The polarization of optical wave through the skin sample was modulated while the variation of the optical field was observed at the imaging plane. The intensity variation curve of each pixel was fitted to extract the near field polarization parameters to form indirect images. During the through-skin light modulation and image retrieving process, the curve fitting removes the blurring scattering from neighboring pixels and keeps only the field variations related to local skin structures. By using the infrared PIMI, we can break the diffraction limit, bring the wide field optical image resolution to sub-200nm, in the meantime of taking advantage of high transmission of infrared waves in skin structures.

A pinhole is usually used as the pupil in traditional optical scanning holography (OSH) method. Although such a structure is relatively simple, the in-focus sectional image may be degraded by out-of-focus haze because of its difficulty to be eliminated in sectional image reconstruction. In this paper, a random-phase pupil is employed in OSH system to reduce the impact of defocus image. It is proved by the experimental results that the defocus image trends to be more easily dispersed into speckle-like pattern, and then it can be removed by connected component method in the future. Analysis also focuses on the correlation coefficient between the original image and the reconstructed images under the conditions of adopting a pinhole or a random-phase pupil. From comparison, as the defocus distance increasing, one can find that the correlation coefficient of image by using a random-phase pupil is decreasing faster than using a pinhole pupil.

Due to its advantageous imaging characteristic and banding flexibility, imaging fiber bundle can be used for line-plane-switching push-broom infrared imaging. How to precisely couple the fiber bundle in the optics system is the key to get excellent image for transmission. After introducing the basic system composition and structural characteristics of the infrared systems coupled with imaging fiber bundle, this article analysis the coupling efficiency and the design requirements of its relay lenses with the angle of the numerical aperture selecting in the system and cold stop matching of the refrigerant infrared detector. For an actual need, one relay coupling system has been designed with the magnification is -0.6, field of objective height is 4mm, objective numerical aperture is 0.15, which has excellent image quality and enough coupling efficiency. In the end, the push broom imaging experiment is carried out. The results show that the design meets the requirements of light energy efficiency and image quality. This design has a certain reference value for the design of the infrared fiber optical system.

For a positioning CMOS camera, we put forward a system which can measure quantitatively dispersed spot parameters and the degree of energy concentration of certain optical system. Based on this method, the detection capability of the positioning CMOS camera can be verified. The measuring method contains some key instruments, such as 550mm collimator, 0.2mm star point, turntable and a positioning CMOS camera. Firstly, the definition of dispersed spot parameters is introduced. Then, the steps of measuring dispersed spot parameters are listed. The energy center of dispersed spot is calculated using centroid algorithm, and then a bivariate-error least squares curve Gaussian fitting method is presented to fit dispersion spot energy distribution curve. Finally, the connected region shaped by the energy contour of the defocused spots is analyzed. The diameter equal to the area which is 80% of the total energy of defocused spots and the energy percentage to the 3×3 central area of the image size are both calculated. The experimental results show that 80% of the total energy of defocused spots is concentrated in the diameter of the inner circle of 15μm, and the percentage to the 3×3 pixels central area can achieve 80% and even higher. Therefore, the method meets the needs of the optical systems in positioning CMOS camera for the imaging quality control.

The determination of optical system parameters is the first step in the design of optical system of star sensor. In this paper, the influence of the field of view, focal length and relative aperture of the optical system on the star sensor is analyzed. In the selected detector conditions, according to the field, the focal length, and the magnitude of threshold of mutual restriction, signal-to-noise ratio, the size of the catalog and optical system design considering the level of to determine the optical system of the field, focal length, relative aperture, magnitude of threshold, spectral range and center wavelength. In order to meet the signal to noise ratio, the stellar detection limit, detection probability and other requirements, the selected detector were calculated. The method of determining the parameters provide a reference for the design of the optical system of star sensor.

Electron optics is a theoretical base of scientific instrument engineering. Mathematical simulation of occurring processes is a base for contemporary design of complicated devices of the electron optics. Problems of the numerical mathematical simulation are effectively solved by CAE system means. CAE “FOCUS” developed by the authors includes fast and accurate methods: boundary element method (BEM) for the electric field calculation, Runge-Kutta- Fieghlberg method for the charged particle trajectory computation controlling an accuracy of calculations, original methods for search of terms for the angular and time-of-flight focusing. CAE “FOCUS” is organized as a collection of modules each of which solves an independent (sub) task. A range of physical and analytical devices, in particular a microfocus X-ray tube of high power, has been developed using this soft.

This paper presents a 10Gb/s partial response (PR) equalizer in 0.18μm CMOS technology. By incorporating a reshaping filter with high-frequency emphasis and the intrinsic roll-off bandwidth of the channel, a duobinary signal is available at the receiver, reducing the bandwidth requirement of high speed communication. To enhance the performance of the PR equalizer, a two-path oversampling technique is used to cope with the time delay variations due to different process corners. Additionally, adjustable capacitance and load calibration technique are also applied to eliminate the process variations further. The chip area including I/O pads occupies 0.835×0.715mm² and the power consumption is about 224mW under 1.8V power supply. Post simulation results show that the proposed equalizer works properly at 10Gb/s and more than 70% eye opening can be obtained.

In general, the terahertz metamaterial filter based on the complementary structure mainly has the fixed resonant frequency and asymmetric resonant frequency edges. In this paper, a thermally control terahertz narrow bandpass filter consisting of a periodic array of complementary wires embedded with thermosensitive semiconductor indium antimonide (InSb) has been proposed. Due to the structure of the filter is relatively simple, it can be more easily fabricated by lithograph technology compared with traditional terahertz metamaterial filter structure. Furthermore, its performance has also been analyzed based on the effective medium theory and the Drude model. The results show that the resonant frequency shifts from 1.16THz to 2.11THz with the increasing of the temperature from 160K to 360K, and the blueshift of resonance frequency as large as 81% can be implemented. Meanwhile, the reflectivity at the resonant frequency almost tends to be zero and the transmissivity spectrum at the resonant frequency exhibits sharp and symmetric edges. The filter can be applied to THz imaging system, and can effectively improve the imaging quality as a result of well characteristics of dynamic tuned filer and relatively simple structure.

By introducing an amplified spontaneous emission source as additional noise, two sets of experimental schemes are designed to measure noise figure characteristics of Erbium-Doped Fiber Amplifier employed in an analog optical system. The impacts of the signal power and the Signal to Noise Ratio on the Noise Figure are systematically measured. The qualitative conclusions are obtained that the decline of the input optical power and improvement of signal to noise ratio will lead a rising Noise Figure of Erbium-Doped Fiber Amplifier. These results will benefits the optimization of the analog optical amplifier by providing the proper working conditions of the Erbium-Doped Fiber Amplifier.

In this paper, the proposed switch of T-type based on photonic crystal ring resonator has been studied. The proposed structure is composed of two waveguides, between them the photonic crystal ring resonator is placed. Our structure can switch two wavelengths together following an external effect. The proposed design has a simple geometric shape, therefore it is capable to realize optical switch applicable to photonic integrated circuits. The parameters that can characterized the performance of optical device are quality factor, crosswalk and foot print. The values of crosstalk, quality factor and footprint that have been obtained are – 41.5db, 330 and 89.38 μm², respectively, which are superior to earlier reported values. The finite different time domain (FDTD) and plane wave extended (PWE) methods are used to calculate the outputs spectrum and band gap, respectively.

Subaperture stitching interferometry has been proven to be a promising method for precision metrology of aspheric surfaces. However, due to the aspheric departure, selection of F/number of the transmission sphere for aspheres is more complicated than spheres or flats. This paper proposed an optimization method to determine the maximum subaperture width based on the slope resolution of the standard interferometer. With it, the transmission sphere is selected with an optimal F/number. On the basis of the transmission sphere and overlap rate, we not only can ensure the fringes of off-axis subapertures are resolvable by the interferometer, but also can minimize the number of subapertures required to cover the full aperture of the surface. Finally, some numerical examples are given to illustrate the procedure, and also to verify the validity of our proposed method.

An adaptive Cylindrical Lens Array (ACLA) for a 2D/3D switchable display is demonstrated. The ACLA is based on two transparent liquids of different refractive indexes and an elastic membrane. Driving these two liquids to flow can change the shape of the elastic membrane as well as the focal length. In this design, the gravity effect of liquid can be overcome. An ACLA demo for the 2D/3D switchable display is developed. The experimental result shows that the ACLA demo works as a light splitting and 2D/3D switching component of the 2D/3D switchable display effectively and the 2D/3D switchable display is realized.

The double-liquid variable-focus lens based on the electrowetting has the characteristics of small size, light weight, fast response, and low price and so on. In this paper, double-liquid variable-focus lens’s Principle and structure are introduced. The reasons for the existence and improvement of contact angle hysteresis are given according improved Young’s equation. At last, 1-Bromododecane with silicone oil are mixed to get oil liquid with different viscosity and proportion liquid as insulating liquid. External voltages are applied to these three liquid lens and focal lengths of the lenses versus applied voltage are investigated. Experiments show that, the decreasing of oil liquid viscosity can reduce focal length hysteresis.

Combining with the fold line videometrics, a method for pose estimation based on monocular measurements is studied. The method to measure the inertial position of the Photometric transfer station and the Orthogonal Iterative Algorithm based on the image space collinearity error is summarized. Then, the mistake using the Singular Value Decomposition (SVD) to solve is described and then introduce the improving algorithm. Finally, the Simulation and actual experiment is done to verify the accuracy of pose estimation using the fold line videometrics. The results show that the precision can reach 1mm or less using a camera with the resolution of 1280 by 1024 pixels, in the condition of 4.5 meter capturing distance and a Leica TS30.

Aiming at the effect of converge laser light scattering caused by subsurface micro-defect, and the change rule of laser scattering modulation was studied. First, the geometry model is built by defect type; then, by finite element method based on electromagnetic theory, the scattering light intensity distribution and variation curve with different detection defect depth, which convergence light spot focus on, were researched by numerical simulation. Finally, simulation model was verified by comparing experiment. This research results are important to setup the mathematical relation between subsurface defect and light scattering, and realize quantitative detection for the subsurface defect of optical element.

Three-dimensional (3-D) shape measurement technology based on structured light has become one hot research field inspired by the increasing requirements. Many methods have been implemented and applied in the industry applications, but most of their equipments are large and complex, cannot be portable. Meanwhile, the popularity of the smart mobile terminals, such as smart phones, provides a platform for the miniaturization and portability of this technology. The measurement system based on phase-shift algorithm and Gray-code pattern under the Android platform on a mobile phone is mainly studied and developed, and it has been encapsulated into a mobile phone application in order to reconstruct 3-D shape data in the employed smart phone easily and quickly. The experimental results of two measured object are given in this paper and demonstrate the application we developed in the mobile platform is effective.

Fringe projection is an extensively applied technique for optical three-dimensional (3-D) shape measurements. Although showing favorable performance for motionless objects, it tends to have difficulties to retrieve surfaces globally or locally varying over time. The reason is that common methods developed for static scenes are prone to fail when measuring dynamic processes. Therefore, to facilitate the application of high-speed real-time measurements, we suggest considerations from four aspects to improve conventional fringe projection methods. The first two aspects are related to raising the measuring efficiency, which can be achieved by encoding the measured object robustly yet with less required patterns, and by increasing the rate of pattern projection which is a bottleneck restricting the measuring speed. The third consideration is to obtain accurate 3-D reconstructions by removing unreliable points induced by system and random errors during dynamic measurements. The last one is to handle moving shiny objects as it is supposed to be a time-consuming process for traditional approaches. We believe the mentioned considerations will help ease the efforts to achieve desired results for fast real-time measurements.

We introduce a high-speed 3-D shape measurement technique based on composite phase-shifting fringes and a stereo camera system. Epipolar constraint is adopted to search the corresponding point independently without additional images. Meanwhile, by analysing the 3-D position and the main wrapped phase of the corresponding point, pairs with an incorrect 3-D position or considerable phase difference are effectively rejected. Then all the qualified corresponding points are corrected, and the unique one as well as the related period order is selected through the embedded triangular wave. Finally, considering that some points can only be captured by a single camera in some shading areas, the final period order of these points in one camera and the one of their corresponding points in another camera always have different values, so left-right consistency check is employed to eliminate those erroneous period orders in this case. Several experiments on both static and dynamic scenes are performed, verifying that our method can achieve a speed of 120 frames per second (fps) with 25-period fringe patterns for fast, dense, and accurate 3-D measurement.

Fringe pattern can be projected fast by digital projector using DLP technology. The projection speed is higher when patterns with lower bit-depth are adopted. The phase error of sinusoidal fringe pattern with different bit-depth is studied with three-step phase-shifting algorithm. The uniform quantization algorithm (UQA) and quantization algorithm with error diffusion (EDA) are used for pattern quantization. The conclusions are as following. 1) With UQA, the maximum of phase error will less than 1% of 2π when bit-depth is higher than 4 bits. If the projector is defocused, the error will be decreased. 2) With EDA, the maximum of phase error is larger than that with UQA. But the error will be decreased significantly when the projector is defocused. The phase error of pattern with EDA is smaller than that of pattern with UQA when the projector is nearly focused and the period of pattern is long (for example longer than 20 pixels). If the period of pattern is short, the performance of UQA is always better. 3) The error difference of UQA and EDA will be very small when the bit-depth is higher than 4 bits.

Empirical mode decomposition (EMD) based methods have been widely used in fringe pattern analysis, including denoising, detrending, normalization, etc. The common problem of using EMD and Bi-dimensional EMD is the mode mixing problem, which is generally caused by uneven distribution of extrema. In recent years, we have proposed some algorithms to solve the mode mixing problem and further applied these methods in fringe analysis. In this paper, we introduce the development of these methods and show the successful results of two most recent algorithms.

The transport of intensity equation (TIE) is a powerful tool for direct quantitative phase retrieval in microscopy imaging. However, there may be some problems when dealing with the boundary condition of the TIE. The previous work introduces a hard-edged aperture to the camera port of the traditional bright field microscope to generate the boundary signal for the TIE solver. Under this Neumann boundary condition, we can obtain the quantitative phase without any assumption or prior knowledge about the test object and the setup. In this paper, we will demonstrate the effectiveness of this method based on some experiments in practice. The micro lens array will be used for the comparison of two TIE solvers results based on introducing the aperture or not and this accurate quantitative phase imaging technique allows measuring cell dry mass which is used in biology to follow cell cycle, to investigate cell metabolism, or to address effects of drugs.

In order to measure spectral transmittance of solar-blind filter ranging from ultraviolet to visible light accurately, a high-precision filter transmittance measuring system based on the ultraviolet photomultiplier is developed. The calibration method is mainly used to measure transmittance in this system, which mainly consists of an ultraviolet photomultiplier as core of the system and a lock-in amplifier combined with an optical modulator as the aided measurement for the system. The ultraviolet photomultiplier can amplify the current signal through the filter and have the characteristics of low dark current and high luminance gain. The optical modulator and the lock-in amplifier can obtain the signal from the photomultiplier and inhibit dark noise and spurious signal effectively. Through these two parts, the low light passing through the filters can be detected and we can calculate the transmittance by the optical power detected. Based on the proposed system, the limit detection of the transmittance can reach 10^-12, while the result of the conventional approach is merely 10^-6. Therefore, the system can make an effective assessment of solar blind ultraviolet filters.

Camera calibration using a 2D planar board is widely applied because of the flexibility and simplicity of this method. However, this technique fails to yield reliable and accurate calibration results when an imperfect planar target is used. The accuracy of the image and world coordinates for the extracted corners, which are prerequisites for deriving precise camera parameters, are affected by the lens distortion and the non-planarity of the calibration target. In this paper, the accuracy of the obtained image coordinates is improved by combining a Hilbert transform with a traditional calibration method. In addition, the geometry of the calibration target is fully considered so as to acquire precise world coordinates using an overall nonlinear parameter optimization algorithm. The reprojection error of the proposed method is reduced by 80% compared with the traditional method for a significantly deformed planar target, which demonstrates the superiority of the proposed camera-calibration technique.

Mental fatigue can be induced by long time mental work, mental fatigue caused worse performance and accidents. As a non-invasive technique, functional near-infrared spectroscopy (fNIRS) can measure blood oxygen activity in the cerebral cortex which reflect the cognitive function of brain indirectly. Aiming at investigating whether fNIRS can measure the mental fatigue and study the spatial pattern of hemodynamic response for mental fatigue, we used three sessions of verbal 2-back working memory task for a total of 120 minutes to induce mental fatigue, 15 healthy subjects were recruited and 30 channels including prefrontal cortex (PFC) and motor cortex (MC) were measured by fNIRS. The mean oxyhemoglobin feature for 20s was extracted as well as subjective fatigue level and performance. The results showed significant increase of subjected fatigue level as well as significant decrease performance from session one to three task. With the increased level of fatigue, oxyhemoglobin in PFC increase significantly and the spatial pattern of hemodynamic response in the all 30 channels varied with task duration as well. These findings indicated the potential of fNIRS measured hemodynamic as a mental fatigue indicator.

In this paper, a method for non-contact detecting the acoustic signal of tank gas leakage based on low-coherence optical fiber interferometer is presented. Vibration signals which caused by acoustic field of gas leakage are detected by low-coherence interference. The experimental results show that the vibration signals are wideband signals (0 Hz~90 KHz). While increasing the internal pressure, high-frequency components of the frequency spectrum have an obvious increasing trend, the amplitude and energy of the acoustic signal will both increase. The minimum detectable internal pressure of tank is 0.12MPa. The sensor is simple and reliable, and has a good practicability.

Surfaces made by Additive Manufacturing (AM) processes normally show higher roughness and more complicated microstructures than conventional machined surfaces. In this study, AM surface roughness measurements using both tactile and optical techniques are analyzed, theoretically and experimentally. Analytical results showed both techniques have comparable performance when measuring AM samples with good surface integrity. For surfaces with steep features, coherence scanning interferometry showed more reliable performance especially when peak-to-valley value was required. In addition of the benchmarking study, development of a low-cost measurement system, using laser confocal technology, is also presented in this paper. By comparing the measurement results with those from a coherent scanning interferometer, accuracy levels of the proposed system can be evaluated. It was concluded that with comparable accuracy, the proposed low-cost optical system was able to achieve much faster measurements, which would make it possible for in-situ surface quality checking.

Laser has several advantages, such as high brightness, excellent directivity, good monochromatic, good coherence and so on [1]. Therefore, in ranging schemes which combine laser sensor technology and automatic control technology [2], the laser ranging is most commonly used nowadays [3]. First, we introduce the principle of grating diffraction in this paper, and proposes a method for ranging based on the laser reflection characteristics of target. Let the laser beam reflected from the target through the diffraction grating and lens and image on the CCD. In the horizontal plane perpendicular to the direction of incidence, grating, lens and CCD make up of an imaging device, and which can measure the distance of target for many times by moving itself horizontally. We can calculate the distance through measuring the range between the central point of the CCD and zero diffraction fringe. Then, we analyze the influence from the targets’ scattering characteristics. Lastly, we simulate the different status according to the proportion of mirror reflection of the actual targets’ scattering characteristics and get a conclusion that only the proportion of mirror reflection exceeds a particular ratio can calculate a valid distance.

We have developed a novel light scattering measurement system based on a microfluidic trap to measure the elastic light scattering of micro-particles. The particles were captured from the sample suspension by a microfluidic chip with a hydrodynamic trapping, which were stably immobilized at the predetermined position by the pressure gradient and friction in the micro-channel. The trapped particles were illuminated by a He-Ne laser after refractive index matching, and a narrow-field photodetector designed by the spatial filter and a photomultiplier mounted on a homocentric rotating platform was used to detecting the scattering light. In this paper, we have improved this measurement system. By reducing the background scattering of microfluidic chip to improve the signal-noise ratio and using precise control, we measured the 23.75μm diameter polystyrene microsphere’s light scattering distribution, the results showed a good agreement on the trend with the curves of theoretical result. At the same time, using the microfluidic trap, we captured two particles (same size and different size) in a fixed orientation with touching components and obtained the light scattering distribution.

Fourier ptychographic microscopy (FPM) is a newly developed super-resolution technique, which employs angularly varying illuminations and a phase retrieval algorithm to surpass the diffraction limit of a low numerical aperture (NA) objective lens. In current FPM imaging platforms, accurate knowledge of LED matrix’s position is critical to achieve good recovery quality. Furthermore, considering such a wide field-of-view (FOV) in FPM, different regions in the FOV have different sensitivity of LED positional misalignment. In this work, we introduce an iterative method to correct position errors based on the simulated annealing (SA) algorithm. To improve the efficiency of this correcting process, large number of iterations for several images with low illumination NAs are firstly implemented to estimate the initial values of the global positional misalignment model through non-linear regression. Simulation and experimental results are presented to evaluate the performance of the proposed method and it is demonstrated that this method can both improve the quality of the recovered object image and relax the LED elements’ position accuracy requirement while aligning the FPM imaging platforms.

We propose an absolute 3D micro surface profile measurement technique based on a Greenough-type stereomicroscope. The camera and the projector are fixed on the stereomicroscope, facilitating a flexible 3D measurement of objects with different heights. Experiments of both calibration and measurements are conducted, and the results show that our proposed method works well for measuring different types of geometry like spheres, ramps and planes etc. The reconstruction accuracy can achieve 4.8 μm with a measurement depth about 3 mm.

In this paper, we describe several new approaches for achieving multi-modal computational imaging, including contrast-enhancement imaging, quantitative phase imaging, light field imaging, and lens-less tomographic imaging, with use of a programmable LED array or a programmable LCD panel.

In this paper, we develop the requisite theory to describe a hybrid virtual-physical multi-modal imaging system which yields quantitative phase, Zernike phase contrast, differential interference contrast (DIC), and light field moment imaging simultaneously based on transport of intensity equation(TIE). We then give the experimental demonstration of these ideas by time-lapse imaging of live HeLa cell mitosis. Experimental results verify that a tunable lens based TIE system, combined with the appropriate post-processing algorithm, can achieve a variety of promising imaging modalities in parallel with the quantitative phase images for the dynamic study of cellular processes.

Today one of the main areas of application of two-photon microscopy is biology. This is due to the fact that this technique allows to obtain 3D images of tissues due to laser focus change, that is possible due to substantially greater penetration depth on the main wavelength into biological tissues. Self-developed microscopy system provides possibility to service it and modify the structure of microscope depending on highly specialized experimental design and scientific goals. This article may be regarded as a quick reference to laboratory staff who are wishing to develop their own microscopy system for self-service and modernization of the system and in order to save the lab budget.

In this study, the influence of the working distance (WD) on strain measurement under a laser scanning microscope and a way to achieve precise focus were investigated by the scanning moiré method. Experimental results showed that the strain measurement has a good repeatability at a fixed WD. Scanning moiré fringes were clearly observable when the WD variation range was within 0.9% of the given WD of the used objective lens. The relationship of the measured strain error and the WD difference was approximately linear, and the greatest strain error was near 700 με. Fortunately, 2D moiré fringes were distinct only in a very narrow range, i.e., the WD difference was less than 0.1% of the given WD, and the greatest strain error was less than 100 με. 1D moiré fringes in the y direction, 2D moiré fringes in the both x and y directions, and 1D moiré fringes in the x direction became distinct alternately along with the WD change. Consequently, we suggest to use 2D moiré fringes for microscale strain measurement in each focusing process to reduce the errors caused by the WD variation. Moreover, a single-shot 2D moiré image is useful to measure the strain distributions in both two directions quickly and simply, and there is no need to rotate the sample or scanning lines and scan twice as in the conventional way.

In the development and production process of laser gyros, reflective mirrors have always been a core component, as they are directly related to the performance of laser gyros. Besides, surface profile deviation and surface defects of mirrors may lead to irreversible serious damages to gyros. In order to achieve effective three-dimensional (3D) quantitative measurements of their surface profiles and defects, we adopt digital holographic microscopy (DHM). Using a DHM system with multiple magnifications and the aberration compensation method, we obtained 3D profile images and estimated the precise quantitative sizes of not only a profile with an aperture of 6.41 mm and a curvature radius of 8.39 m, but also a scratch with a line-equivalent width of 0.45μm and an equivalent depth of 137.28 nm and a pit with an equivalent diameter of 0.86μm and an equivalent depth of 42.95 nm. These results demonstrate that the method is feasible and effective to meet the requirements of engineering practice.

Performance of a range gated system is strongly affected by the laser, sensor, target, and atmospheric parameters. This paper performs a theoretical analysis to investigate the influence of multiple factors on range gated reconstruction. The effects of several factors are discussed based on the operating principle of range gated reconstruction, fundamental of radiant energy, signal to noise ratio (SNR), and bidirectional reflection distribution function (BRDF) models. The presented findings establish a comprehensive understanding of the influence factors in range gated reconstruction which are of interest to various applications and future improvement works to perform accurate range correction and compensation.

In this paper, a method for individual tree shape modeling and canopy coverage delineation is provided for high density airborne LiDAR data. Three basic 3-D canopy shape models are introduced as fundamental assumptions, and then an iterative algorithm for calculating tree canopy window is implemented. After that, the prototype test is carried out with simulated forest point data which visually shows a valid result. After that, a real mixed forest LiDAR dataset is being put into experiment. Based on the same theory, the output and a statistical analysis reveals that the proposed method can yield an effective and distinguishable extraction of different tree canopy coverage delineation.

In high-power and high-energy laser measurement, the absorber materials can be easily destroyed under long-term direct laser irradiation. In order to improve the calorimeter's measuring capacity, a measuring system directly using water flow as the absorber medium was built. The system's basic principles and the designing parameters of major parts were elaborated. The system's measuring capacity, the laser working modes, and the effects of major parameters were analyzed deeply. Moreover, the factors that may affect the accuracy of measurement were analyzed and discussed. The specific control measures and methods were elaborated. The self-calibration and normal calibration experiments show that this calorimeter has very high accuracy. In electrical calibration, the average correction coefficient is only 1.015, with standard deviation of only 0.5%. In calibration experiments, the standard deviation relative to a middle-power standard calorimeter is only 1.9%.

In the designed reference beam laser Doppler velocimeter (LDV) for the vehicle self-contained navigation system, the reference object is a kind of solid-state surface. This paper expounded the generation mechanism of reference beam laser Doppler signal of this solid-state surface according to the order of the speckle field intensity variation. The expression of reference beam laser Doppler signal intensity of solid-state surface is derived based on the theory of speckle and stochastic process. Results of theory and experiments show that the essence of reference beam laser Doppler signal of solid-state surface is the coherence stack of two speckles. The signal intensity is directly proportional to the diameter of the photosensitive surface of detector and is inversely proportional to the diameter of laser spot on ground.

The performance of radio frequency (RF) exciting He-Ne laser is exposed. This text sets out from kinetics property of the electronics inside the high-frequency, aiming at getting the relationship between radio frequency and plasma energy. In order to study the frequency characteristic of RF excitation in He-Ne laser, the frequency ranging from 300MHz to 700MHz is chose to test the discharge property of active medium. It also obtains the optimal RF frequency (432MHz) through experiment, which is important to the improved design of RF exciting He-Ne laser.

Biological laser printing (BioLP) is a promising biomaterial printing technique. It has the advantage of high resolution, high bioactivity, high printing frequency and small transported liquid amount. In this paper, a set of BioLP device is design and made, and protein microarrays are printed by this device. It’s found that both laser intensity and fluid layer thickness have an influence on the microarrays acquired. Besides, two kinds of the fluid layer coating methods are compared, and the results show that blade coating method is better than well-coating method in BioLP. A microarray of 0.76pL protein microarray and a “NUDT” patterned microarray are printed to testify the printing ability of BioLP.

For an unknown characteristic target scene, the laser radar system that uses single-photon detector cannot directly estimate the dwell time of every pixel. Therefore, as the difference of target reflectivity, depth estimation appears inadequate sampling or redundant sampling in the conventional imaging method of maximum likelihood estimation (MLE-CIM). In this work, an adaptive depth imaging method (ADIM) is presented. ADIM is capable to obtain the depth estimation of target and adaptively decide the dwell time of each pixel. The experimental results reveal that ADIM can accurately obtain the 3D depth image of target even at the condition of low signal-to-noise ratio.

Mid-infrared laser spectroscopy provides an ideal platform for trace gas sensing applications. Despite this potential, early MIR sensing applications were limited due to the size of the involved optical components, e.g. light sources and sample cells. A potential solution to this demand is the integration of hollow fiber waveguide with novelty quantum cascade lasers.Recently QCLs had great improvements in power, efficiency and wavelength range, which made the miniaturized platforms for gas sensing maintaining or even enhancing the achievable sensitivity conceivable. So that the miniaturization of QCLs and HWGs can be evolved into a mini sensor, which may be tailored to a variety of real-time and in situ applications ranging from environmental monitoring to workplace safety surveillance. In this article, we introduce QCLs and HWGs, display the applications of HWG based on QCL gas sensing and discuss future strategies for hollow fiber coupled quantum cascade laser gas sensor technology.

A tunable diode laser absorption spectroscopy (TDLAS) system based on a broad band external cavity quantum cascade laser (ECQCL) near 7.78 μm was used to study volatile organic compounds (VOCs) measurements. Instead of using a standard infrared mercury cadmium telluride (MCT) detector, a quartz crystal tuning fork (QCTF) as a light detector was successfully used for laser signal detection. Fast Fourier transform (FFT) was used to extract vibration intensity information of QCTF. Primary results indicate that the new developed system has a good reproducibility, and a good agreement was obtained by comparing with data taken from standard spectroscopic database.

Differential confocal theta microscope (DCTM) which has high axial resolution, provides a feasible tool for precise measurement. The virtual pinhole detection technology can significantly simplify the optical path alignment, and enhance imaging quality of the system by optimizing virtual pinhole parameters. Based on the imaging principle of DCTM, a new method for automatic adjusting and optimizing virtual pinhole parameters is presented according to the position and size of the imaging spot, which eliminate the influence caused by the deformation and shifting of imaging spot and ensure the axial resolution. The theoretical analyses and experimental results show that optimizing virtual pinhole parameters can guarantee the axial resolution and signal-to-noise ratio as well as effectively improve the imaging quality of DCTM.

Pupil parameters are important parameters to evaluate the quality of lithography illumination system. In this paper, a cloud based full-featured pupil processing application is implemented. A web browser is used for the UI (User Interface), the websocket protocol and JSON format are used for the communication between the client and the server, and the computing part is implemented in the server side, where the application integrated a variety of high quality professional libraries, such as image processing libraries libvips and ImageMagic, automatic reporting system latex, etc., to support the program. The cloud based framework takes advantage of server’s superior computing power and rich software collections, and the program could run anywhere there is a modern browser due to its web UI design. Compared to the traditional way of software operation model: purchased, licensed, shipped, downloaded, installed, maintained, and upgraded, the new cloud based approach, which is no installation, easy to use and maintenance, opens up a new way. Cloud based application probably is the future of the software development.

A sensitive open-path gas sensor employing a continuous-wave (CW) distributed feedback (DFB) quantum cascade laser (QCL) and direct absorption spectroscopy (DAS) was demonstrated for simultaneously measurements of atmospheric CO and N₂O. Two interference free absorption lines located at 2190.0175 cm^-1 and 2190.3498 cm^-1 were selected for CO and N₂O concentration measurements, respectively. The Allan variance analysis technique was performed to investigate the long-term performance of the QCL sensor system. The results indicate that a detection limit of 9.92 ppb for CO and 7.7 ppb for N₂O with 1-s integration time were achieved, which can be further improved to 1.5 ppb and 1.1 ppb by increasing the average time up to 80 s.

In this paper, we presented a waveform reconstruction method based on the self-mixing interference of DFB fiber laser by phase modulating technique, which is superior to the traditional vibration measurement system due to the wider measurement range and higher accuracy. In our sinusoidal phase modulation technology, the vibration information of the external target is extracted by the Fourier transformation method. For restoring the micro-vibration of the external target effectively with high precision, theoretical analysis and numerical simulations of phase modulation method based on the Distribution Feedback Bragg fiber laser are introduced in detail.

A method for the measurement of the absolute distance based on wavelength tuning technology of DBR fiber laser is presented. Experimental results show that the fringe number of the self-mixing signal and the target distance can reach a good linear relationship which agreed with the simulation results well. This paper demonstrate that DBR fiber laser present a powerful tool for the self-mixing technique and provide measurement of the distance up to 3.33 meters.

Thermal damage for material with the presence of a cone defect is studied. Firstly, a three-dimensional thermal damage model is established. Then, the distribution of electric field intensity and temperature of defective Si irradiated by laser pulse is calculated by the method of FDTD. At the same time, melting threshold of the Si material with defect is calculated and its variation rule with the height of the defect is analyzed. The results show that, the redistributed electric field is different in different depth of material. The maximum electric field intensity in the plane of each xOy is periodically changed over the height of material. The maximum electric field intensity in the first period near the surface is the crest value throughout the material. The value of melting threshold of material is the lowest when height of defect is 240 nm.

The theoretical model of single bubble movement in an ideal solution, to carry on the numerical simulation of the process of cavitation in the liquid, the liquid in different laser energy, laser induced cavitation rules and acoustic characteristics were studied by high-speed camera, high frequency measurements of the hydrophone. The results show that with the increase of laser energy, the period of bubble pulsation and the maximum bubble radius increase gradually, and the amplitude of the laser acoustic signal becomes larger.

The equation of laser detection system range and multi-wavelength conversion technique were used to calculate the maximum detection range under different meteorological conditions. A new algorithm was proposed to solve the detection range implicit function equation, by which the accurate arithmetic solution could be got quickly. When solving the detection range implicit function equation, the atmospheric transmittance is the function of range, the multiwavelength atmospheric extinction coefficients were calculated with neural network conversion model. Then the equation was solved by linear interpolation and iteration methods, the iteration initial value was estimated with numeric method. This algorithm is valuable for simulating, model building and designing of multi-wavelength laser system under different seasons and atmospheric circumstance.

In this paper, a new means of measuring the displacement of GMA (Giant Magnetostrictive Actuator) based on FGB (Fiber Bragg Grating) sensor is proposed, experimental results confirmed that FGB sensor can measure the displacement of GMA in different frequencies and achieve good results. In addition a modified Bouc-Wen model is presented to describe the GMA, the proposed model can describe the asymmetric hysteresis of GMA from 1 Hz to 100 Hz well, and DE(Differential Evolution) algorithm is used for adaptive identification of the GMA system, the algorithm has fast convergence and high accuracy. Finally, it verifies that the identification model fits the experimental data well.

Plasmon waveguides were fabricated by coating sol-gel copolymer templated nanoporous TiO₂ films on gold layers sputtered on glass substrates, and they were used to construct wavelength-interrogated plasmon waveguide resonance (PWR) sensors with Kretschmann configuration. The cross-sectional image of the plasmon waveguide obtained with scanning electron microscope indicates that the gold and nanoporous TiO₂ films are about 40 nm and 290 nm thick. The resonance wavelength (λ_R) of the PWR sensor at a given incident angle is determined from either the reflected light intensity spectrum or the absorption spectrum. The porosity of TiO₂ film was determined to be ca. 0.42 by a comparison between simulation and experimental results. The PWR sensor operates with transverse electric mode. The in-situ and ex-situ responses of the PWR sensor to glutathione (GSH) adsorption were investigated theoretically and experimentally. The simulation results show that with either in-situ or ex-situ measurement the resonance wavelength linearly increases with increasing GSH concentration and the slope with ex-situ method is 6 times larger than that with in-situ method. The PWR sensor’s response to GSH adsorption from the 100 μmol/L solution was measured to be Δλ_R = 31 nm with ex-situ detection and Δλ_R = 6.1 nm with in-situ detection. Both the experimental and simulation investigations reveal that the ex-situ detection sensitivity is much higher than the in-situ one for the PWR sensor. The work suggests that the ex-situ detection method can offer the PWR sensor a lower detection limit in contrast with the in-situ method.

A wavelength-interrogated surface plasmon resonance (SPR) sensor overlaid with a Teflon AF2400 film was prepared for rapid and sensitive detection of Benzo[a]pyrene (BaP) in water. The thickness of the Teflon AF 2400 film is much larger than the penetration depth of plasmon field, making the SPR sensor insensitive to refractive index (RI) of bulk solution and particle adsorption on the film surface. The sensor is only responsive to changes in RI of the Teflon film. The Teflon AF 2400 film is highly hydrophobic, enabling to effectively absorb nonpolar BaP molecules in water. Since BaP is a high-RI (n = 1.887) compound, its enrichment in the Teflon film can result in a considerable increase of the film RI. Consequently, the SPR sensor operating in the visible-near infrared reflection (NIR) wavelength range can be used to detect very low concentration of BaP in water. According to the simulation results, the thickness of the Teflon film should exceed 1000 nm to eliminate the SPR sensitivity to RI of bulk solution. The experimental results indicate that the resonance-wavelength shift (ΔλR) of the SPR sensor linearly increases with increasing the BaP concentration from C = 20 nmol·L^-1 up to 100 nmol·L^-1. ΔλR is about 0.9 nm at C = 20 nmol·L^-1, which is very close to the minimum ΔλR detectable with the CCD spectrometer used. The resonance wavelength stabilized 6 seconds after the sample injection, indicating that the diffusion of BaP molecules in the Teflon film is quite quick, which is attributable to the nanoporous structure of the Teflon film. It is anticipated that the sensitivity of SPR sensor to BaP and its detection limit can be further improved by optimization of the thickness of the Teflon film.

In this study, we evaluated the influence of retrieval algorithms and sensor characteristics, such as spectral resolution (SR) and signal to noise ratio (SNR), on the retrieval accuracy of fluorescence signal (Fs). Here Fs was retrieved by four commonly used retrieval methods, namely the original Fraunhofer Line Discriminator method (FLD), the 3 bands FLD (3FLD), the improved FLD (iFLD) and the spectral fitting method (SFM). Fs was retrieved in the oxygen A band centered at around 761nm (O2-A). We analyzed the impact of sensor characteristics on four retrieval methods based on simulated data which were generated by the model SCOPE (Soil Canopy Observation, Photochemistry and Energy fluxes), and obtained consistent conclusions when compared with experimental data. Results presented in this study indicate that both retrieval algorithms and sensor characteristics affect the retrieval accuracy of Fs. When applied to the actual measurement, we should choose the instrument with higher performance and adopt appropriate retrieval method according to measuring instruments and conditions.

Thin films of nanoporous gold (NPG) have both localized and propagating surface plasmon resonance (SPR) effects. The propagating SPR effect of NPG film combined with its huge internal surface area makes it applicable as an evanescent wave sensor with high sensitivity. In this work, NPG films with controlled thicknesses were fabricated on glass substrates by sputtering deposition of AuAg films followed by dealloying in nitric acid. By using of the NPG films as the sensing layer, a broadband wavelength-interrogated SPR sensor was prepared for chemical and biological detection. The propagating SPR absorption band in the visible-near infrared region was clearly observed upon exposure of the NPG film to air, and this band was detected to move to longer wavelengths in response to adsorption of molecules within the NPG film. Simulations based on Fresnel equations combined with Bruggeman approximation were carried out for optimizing the propagating SPR property of NPG film. The sensor’s performance was investigated using both bisphenol A (BPA) and lead (II) ions as analytes. According to the experimental results, the detection limits of the sensor are 5 nmol·L^-1 for BPA and 1 nmol·L^-1 for lead (II) ions. The work demonstrated the outstanding applicability of the NPG film based SPR sensor for sensitive environmental monitoring.

Aiming at 45-element adaptive optics system, the model of 45-element deformable mirror is truly built by COMSOL Multiphysics, and every actuator’s influence function is acquired by finite element method. The process of this system correcting optical aberration is simulated by making use of procedure, and aiming for Strehl ratio of corrected diffraction facula, in the condition of existing different translation and rotation error between Hartmann-Shack sensor and deformable mirror, the system’s correction ability for 3-20 Zernike polynomial wave aberration is analyzed. The computed result shows: the system’s correction ability for 3-9 Zernike polynomial wave aberration is higher than that of 10-20 Zernike polynomial wave aberration. The correction ability for 3-20 Zernike polynomial wave aberration does not change with misalignment error changing. With rotation error between Hartmann-Shack sensor and deformable mirror increasing, the correction ability for 3-20 Zernike polynomial wave aberration gradually goes down, and with translation error increasing, the correction ability for 3-9 Zernike polynomial wave aberration gradually goes down, but the correction ability for 10-20 Zernike polynomial wave aberration behave up-and-down depression.

In this paper, the phase information of a railway wheel tread is obtained based on Phase-measuring profilometry, meanwhile, the height information is reconstructed by two phase-height mapping algorithms. The first is traditional phase-height mapping algorithm, which needs translatingds the reference plane several times. Due to the reconstruction of the height information influenced by abrupt phase changes while moving the reference plane, the phase information needs to be converted to be the real phase information. In order to obtain accurate parameters, the reference plane needs to be translated several times, which is a complex procedure. Besides, the calculation is also complicated because of different coefficients in different pixels. The second method is the new phase-height mapping algorithm, which needs building the relationship between phase and height based on seven height-known circular cones. The new method could divide the calibration coefficients and coordinates efficiently. Only the common coefficients that are not related to the sample coordinates are required during calibration, which would decrease the amount of calibration points. There is a comparison between the traditional method and the new method in this paper, and it concludes that the traditional method could make the result more accurate but the new method could be more convenient.

Absorption-based optical sensors have been developed for the determination of water pH. In this paper, based on the preparation of a transparent sol–gel thin film with a phenol red (PR) indicator, several calculation methods, including simple linear regression analysis, quadratic regression analysis and dual-wavelength absorbance ratio analysis, were used to calculate water pH. Results of MSSRR show that dual-wavelength absorbance ratio analysis can improve the calculation accuracy of water pH in long-term measurement.

Portable 3D scanning systems are increasingly used in many applications at present as a result of its high flexibility, portability and high efficiency. Iterative closest points method is widely used for multi-view measurement results registration. However, there are many restrictions for portable system, the alignment often depends on landmarks on object surface or object features, in some applications, it may not achieve satisfactory expectations. In this paper, we propose to conduct the registration based on pose estimation from a low cost inertial sensor, which will increase the measurement effectiveness. Test result demonstrates that the method is feasible. With attitude information inside the system, the measurement device does not need external support information and has good prospects for application.

Realizing long-distance quantum key distribution (QKD) in fiber channel where classical optical communications and quantum signals are multiplexed by their different wavelengths has attracted considerable attentions. The achievable secure distance of commonly-used Bennet-Brassard 1984 (BB84) protocol is lowered severely due to inevitable crosstalk from classical optical pulses. Unlike conventional quantum key distribution (QKD) protocols, round-robin differential-phase-shift (RRDPS) QKD protocol has a high tolerance for noise, since the potential information leakage in this protocol can be bounded without monitoring signal disturbance. Thus, it may be a promising protocol under noisy channel. In this work, we investigate the performance, e.g., achievable secure distance of RRPDS protocol, when crosstalk from classical communication is considered. Surprisingly, we find that RRPDS only has quite limited advantage over BB84 protocol when optical misalignment of QKD system is serious. If misalignment is trivial, BB84 can even outperform RRDPS protocol.

The mechanism of high power intra-channel crosstalk attack is analyzed theoretically and the conclusion that power of attack signal and crosstalk coefficient of optical switch are the main factors for which high power intra-channel have destructive effect on quality of legitimate signals is drawn. Effects of high power intra-channel crosstalk attack on quality of legitimate signals and its capability of attack propagation are investigated quantitatively by building the simulation system in VPI software. The results show that legitimate signals through the first and the second stage optical switch are affected by attack and legitimate signal through the third stage optical switch is almost unaffected by attack when power of original attack signal (OAS) is above 20dB more than that of legitimate signals and crosstalk coefficient of optical switch is -20dB at optical cross connect 1 (OXC1). High power intra-channel crosstalk attack has a certain capability of attack propagation. Attack capability of OAS can be propagated to OXC3 when power of OAS is 27dB more than that of legitimate signals and crosstalk coefficient of optical switch is -20dB. We also find that the secondary attack signal (SAS) does not have capability of attack propagation.

Long-wave infrared wireless communication has much advantage over short-wave infrared. In this paper, the bit error rate performance of LWIR by DPIM is analyzed. The intensity fluctuations of the optical signal are modeled by log-normal distribution, the intensity attenuations are modeled by empirical formula of fog. The system noise includes generation-recombination noise and thermal noise typically for Photoconductive HgCdTe detector. The numerical results of BER are presented. The results illustrate the BER depends on the turbulence strength, bit rate, optical power and link length.

The speckle correlation technique is applied to ciphertext-only attack (COA) on optical cryptosystem based on double random phase encoding. According to the inherent merits of speckle correlation, we have revealed a fact that the ciphertext’s autocorrelation is essentially identical to the plaintext’s own autocorrelation. Then, a plaintext image can be directly reconstructed from the autocorrelation of its corresponding ciphertext by employing a iterate phase-retrieval algorithm. This could then lead to a potential security flaw because an unauthorized user could directly retrieve the plaintext from an intercepted ciphertext by performing proposed COA approach. Meanwhile, a series of numerical simulations will also be provided to verify the validity and feasibility of our proposed COA method.

Many studies have been made in refine transmission to improve the de-haze quality. Compared by several common method of refine transmission, we present an improved refine transmission method of secondary filter to improve halo effect in this paper. Halo effect area is determined by the difference between the estimate transmission and the transmission refined by guided filter. The transmission which is refined by guided filter in halo effect area is replaced by the transmission refined by median filter. Using this method, the too high transmission in halo effect area will be refined. The refine transmission method present by this paper, which combine the advantages of median filter algorithm and the guided filter algorithm. This method can avoid black spots caused by median filter algorithm and halo effect residues caused by guided filter algorithm.

Since electrowetting has been proposed, researchers began to apply eletrowetting into different fields, such as lab-on-chip systems, display technologies, printings and optics etc. This paper mainly introduced structure, theory and application of optical devices based on electrowetting. The optical devices include liquid optical prism, liquid optical lens and display. The paper introduced their principle, specific application and many advantages in optical applications. When they are applied to optical system, production and experiment, they can reduce mechanical moving parts, simplify the structure, operate easily, decrease manufacturing cost and energy consumption, improve working efficiency, and so on. We learn and research them in detail that will contribute to research and develop optical eletrowetting in the future.

Addressing the problems of infrared small target tracking in forward looking infrared (FLIR) system, a new infrared small target tracking method is presented, in which features binding of both target gray intensity and spatial relationship is implemented by compressive sensing so as to construct the Gaussian mixture model of compressive appearance distribution. Subsequently, naive Bayesian classification is carried out over testing samples acquired with non-uniform sampling probability to identify the most credible location of targets from background scene. A series of experiments are carried out over four infrared small target image sequences with more than 200 images for each sequence, the results demonstrate the effectiveness and advantages of the proposed method in both success rate and precision rate.

In recent years, the study of haze has become a hot topic because the fog haze problems have become more and more serious. Under the condition of the infrared and visible light, we have calculated the scattering properties of the smoke haze particles, soluble fog particles, dust haze particles and sea fog particles, respectively. And through the analysis of the calculation results, we concluded that, in the infrared and visible bands, the scattering efficiency, absorb efficiency and extinction efficiency of the same fog particles is all consistent with the same or similar laws.

The curing process of epoxy resin was monitored real-time by using embedded fiber Bragg grating (FBG) sensor. The resin was cured at room temperature 24°C for 24 hours. The curing monitor test showed that the temperature inside the resin went up quickly at the first 70 minutes. Then the temperature increased slowly till 120 minutes. Afterward, the central wavelength decreased which indicated two stage of curing, i.e. temperature reduction and curing shrinkage. Furthermore, the cured resin sample under tensile load was studied. Strain gauges were applied in order to evaluate the FBG sensor. Experimental results showed that difference existed between the mentioned sensors.

Digital image correlation (DIC) is widely applied in optical measurement field. In this work, the classical DIC algorithm is modified to improve the speed and enhance the measurement accuracy. A Butterworth function is installed on the traditional sum-of-squared differences correlation criterion. And inverse compositional Gauss-Newton is carried out. The computer generated speckle patterns are used to demonstrate the presented algorithm. The results declare the proposed method can improve the speed with enhanced measurement accuracy.

In this paper, we proposed a novel optical encryption and decryption method of gray image based on the computer-generated hologram (CGH), the chaos theory and the logical modulation. In the encryption process, the hologram, which is gotten by Fresnel diffraction from the gray image, is modulated with the chaotic sequence, and the output is encryption image. The decryption is an inverse process of encryption. Experiment results verified the security and robustness of the proposed approach. Moreover, the proposed encryption method could be applied in where requires more security and more flexibility as the field of national defense science and technology.

Phase analysis techniques of fringe patterns have been widely used for noncontact three-dimensional shape and deformation measurement by the fringe projection method. Recently, we developed two novel accurate phase analysis methods. One is the two-dimensional sampling moiré method to perform robust phase analysis for a single-shot fringe pattern. The other is the two-dimensional spatiotemporal phase-shifting method to analyze phase distribution accurately for multi-step phase-shifted fringe patterns. To perform accurate phase analysis under low signal-to-noise ratio conditions, both the above two methods use the two-dimensional discrete Fourier transform or fast Fourier transform. Therefore, these algorithms are computationally expensive compared with the conventional one-dimensional sampling moiré and phase-shifting methods. In this study, a fast parallelization implementation for two-dimensional phase-shifting methods, including the two-dimensional sampling moiré method and the spatiotemporal phase-shifting method, are presented by utilizing multi-core CPU. Simulation and experimental results demonstrate that phase analysis can reach 7.5 and 5.9 times faster by use of a 12-core CPU compared with a single CPU.

Computational ghost imaging (CGI) is mainly used to reconstruct grayscale images at present and there are few researches aiming at color images. In this paper, we both theoretically and experimentally demonstrate a colored adaptive compressed imaging method. Benefiting from imaging in YUV color space, the proposed method adequately exploits the sparsity of U, V components in the wavelet domain, the interdependence between luminance and chrominance, and the human visual characteristics. The simulation and experimental results show that our method greatly reduces the measurements required, and offers better image quality compared to recovering red (R), green (G) and blue (B) components separately in RGB color space. As the application of single photodiode increases, our method shows great potential in many fields.

In the application of aperture laser radar, in order to improve the range resolution of image, in general adopting linear modulation signal. But in practice, the transmitting signal of tunable laser is linear wavelength modulation. In order to make clear the effect of linearity of tunable laser to the quality of synthetic aperture laser radar’s image, the expression of linearity of linear wavelength modulation signal has been developed according to the definition of linearity and the effect of linear wavelength modulation signal to the quality of synthetic aperture laser radar’s image has been analyzed. The result shows that the same influence trend that with the pulse during time and coefficient of wavelength-modulated increase, the linearity increase and the quality of synthetic aperture laser radar’s image deteriorate and that the increasing carrier wavelength do the reverse. And further a step, the linearity and the quality of synthetic aperture laser radar’s image have been positive correlative, so the linearity deteriorates the range resolution of laser radar.

This paper proposes a relative pose estimation approach based on object contour model. The first step is to obtain a two-dimensional (2D) projection of three-dimensional (3D)-model-based target, which will be divided into 40 forms by clustering and LDA analysis. Then we proceed by extracting the target contour in each image and computing their Pseudo-Zernike Moments (PZM), thus a model library is constructed in an offline mode. Next, we spot a projection contour that resembles the target silhouette most in the present image from the model library with reference of PZM; then similarity transformation parameters are generated as the shape context is applied to match the silhouette sampling location, from which the identification parameters of target can be further derived. Identification parameters are converted to relative pose parameters, in the premise that these values are the initial result calculated via iterative refinement algorithm, as the relative pose parameter is in the neighborhood of actual ones. At last, Distance Image Iterative Least Squares (DI-ILS) is employed to acquire the ultimate relative pose parameters.

Micro satellites have been widely used in the target monitoring and tracking. Aimed to reduce the ground operator's workload, a target location method based on homography and scene matching is proposed in this paper. For the first time satellite flies over target area, it needs the operator to take a frame as a reference image and extract the target area which is regarded as plane scene. When the satellite scan the area again, we take a frame as a real-time image and calculate the homography induced by the plane. Then rectify the reference image with the homography to reduce distortion between the two images. Finally, locate target on the real-time image using matching method. A significant-feature-point auxiliary positioning method is also proposed to adapt to target area without obvious features. It adopts affine model to calculated target location on the real-time image. Simulation experimental results show accuracy and practical value for engineering of the proposal method.

Super-resolution method based on sparse reconstruction is an effective way to deal with the closely spaced objects problem, but when the targets in a noisy environment, the noise will cover over the entire field, leading to the sparsity feature of the original scene is destroyed. Aiming at this phenomenon, this paper proposed a super-resolution method which has the adaptative reconstruction ability in noisy environments, this method takes full advantage of the structural characteristics of the sensor and the reconstruction algorithm parameters, through the establishment of infrared imaging model of the observed signals and pixel meshing, establishment of the position and amplitude of the closely spaced objects of sparse representation, and using the point spread function of the optical system to construct over-complete dictionary, the last step is making the reconstruction parameters in a reasonable range through controlling the ratio of non-zero elements in the rebuilt scene, so as to achieve the purpose of removing noise interference and reconstruction of sparse targets accurately. Simulation results show that the proposed method with adaptive reconfiguration in noisy environments.

In this work, we propose an laser-interference based measurement method that employs a hardware device in the reference arm to track the out-of-plane displacement in the objective arm. Then a real-time one-point out-of-plane displacement measurement system is built up using a Michelson interferometer, a PZT device, a CCD camera and a tracking control system. The system works by checking the movement of fringes and then promoting PZT to track the displacement. A tracking algorithm including direction judgment and correlation computation is developed to decide whether PZT is started and the distance that PZT is ordered to move. Experimental results demonstrate the effectiveness of the system and finally the detailed mechanism of the system is discussed.

A new wake bubble processing method based on standard images is developed. The distribution, size, population, movement of bubbles in ship wakes are most important characteristic influencing the sonic, optical, conductive and other signatures of ship wakes as information sources for detecting and tracing moving target in sea. The intuitive and effective method to get the parameters of wake bubbles is optical imaging. Standard bubble images can be one of the means of evaluating the performance of imaging processing method. The standard sequence bubble images are generated which the size, velocity, position of bubbles and the width of laser sheet are known and can be changed. The effectiveness and accuracy of the wake bubble image processing method can be evaluated by standard images.

In order to solve the problem of the bandwidth limitation of the image transmission system on UAV, a scheme with image compression technology for mini UAV is proposed, based on the requirements of High-definition image transmission system of UAV. The video codec standard H.264 coding module and key technology was analyzed and studied for UAV area video communication. Based on the research of high-resolution image encoding and decoding technique and wireless transmit method, The high-resolution image transmission system was designed on architecture of Android and video codec chip; the constructed system was confirmed by experimentation in laboratory, the bit-rate could be controlled easily, QoS is stable, the low latency could meets most applied requirement not only for military use but also for industrial applications.

Nonlinear intensity response, namely gamma effect, of the projector-camera setup introduces phase error in phase-shifting profilometry. This paper presents a comparison of three phase error compensation methods: active, passive and adaptive, using a universal phase error model. The active method calibrates a gamma factor to modify the projected fringe patterns; the passive method implement an iterative procedure to work out an optimal phase map; the adaptive method compensate phase error based on Hilbert transform without any auxiliary conditions. Comparison Experiments were implemented in three and four phase-shifting steps, which demonstrated that the active method provided an excellent performance regardless the phase-shifting step, yet the passive method might fail when the phase error was large; the adaptive method could be in the same level as the passive method in four phase-shifting step.

The multi-angle polarization technique, which uses the intensity of polarized radiation as the observed quantity, is a new remote sensing means for earth observation. With this method, not only can the multi-angle light intensity data be provided, but also the multi-angle information of polarized radiation can be obtained. So, the technique may solve the problems, those could not be solved with the traditional remote sensing methods. Nowadays, the multi-angle polarization technique has become one of the hot topics in the field of the international quantitative research on remote sensing. In this paper, we firstly introduce the principles of the multi-angle polarization technique, then the situations of basic research and engineering applications are particularly summarized and analysed in 1) the peeled-off method of sun glitter based on polarization, 2) the ocean color remote sensing based on polarization, 3) oil spill detection using polarization technique, 4) the ocean aerosol monitoring based on polarization. Finally, based on the previous work, we briefly present the problems and prospects of the multi-angle polarization technique used in China’s ocean color remote sensing.

The observations of marine boundary layer NO₂ vertical column density (VCD) over the yellow sea near Qingdao by ship-borne Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) were conducted with a Chinese oceanographic research vessel, XYH 08, during an offshore observation campaign, from 13 September 2015 to 18 September 2015. During the observation campaign, the ship-borne MAX-DOAS system made anchor point measurements in different sea areas including Qingdao coastal waters, the Yellow Sea, the Jiaozhou Bay and the Yangkou Bay area. Measurements results of anchor point measurements are presented in this paper. The air mass factor (AMF) errors caused by the vibration of the ship are also studied in this paper. Under good sea conditions on 14 September, the AMF errors of NO₂ measurements caused by the ship vibration were evaluated to be less than 5%. By combining geometric character of monitoring area and weather condition, it can be concluded from the Jiaozhou Bay and the Yellow Sea measurement results that the meteorological conditions cause significant influence on local boundary layer NO₂ content. The comparison of different anchor point measurements showed that the Jiaozhou Bay sea area had much more NO₂ content than Yangkou sea area because the Jiaozhou Bay sea area is located in Qingdao urban area with surrounding NO₂ contamination.

We propose a micro-vibration detection method by introducing heterodyne interferometry to time-averaged holography. This method compensates for the deficiency of time-average holography in quantitative measurements and widens its range of application effectively. Acousto-optic modulators are used to modulate the frequencies of the reference beam and the object beam. Accurate detection of the maximum amplitude of each point in the vibration plane is performed by altering the frequency difference of both beams. The range of amplitude detection of plane vibration is extended. In the stable vibration mode, the distribution of the maximum amplitude of each point is measured and the fitted curves are plotted. Hence the plane vibration mode of the object is demonstrated intuitively and detected quantitatively. We analyzed the method in theory and built an experimental system with a sine signal as the excitation source and a typical piezoelectric ceramic plate as the target. The experimental results indicate that, within a certain error range, the detected vibration mode agrees with the intrinsic vibration characteristics of the object, thus proving the validity of this method.

The problems caused by the cavitation bubble and caused many adverse effects on the ship propeller, hydraulic machinery and equipment. In order to research the production mechanism of cavitation bubble under different conditions, cavitation bubble zone parameter fine measurement and analysis technology is indispensable, this paper adopts a non-contact measurement method of optical autonomous construction of binocular stereo vision measurement system according to the characteristics of cavitation bubble, the texture features are not clear, transparent and difficult to obtain, 3D imaging measurement of cavitation bubble using composite dynamic lighting, and 3D reconstruction of cavitation bubble region and obtained the characteristics of more accurate parameters, test results show that the cavitation bubble characteristics of the fine technology can obtain and analyze cavitation bubble region and instability.

The point of this article is introducing the usage of electronic power steering (ESP) system in IKCO SAMAND vehicle and investigating on it’s benefit’s. Also the operation of electronic steering system and it’s performance in IKCO SAMAND vehicle have been described. The optimization of IC engine efficiency and it’s fuel consumption have been simulated via ADVISOR software used in MATLAB software. Usually, mechanical steering systems and hydraulic steering systems are producing inside IRAN that the mechanical types have not accepted because of it’s too many disadvantages. The hydraulic steering systems, that have been replaced with mechanical types, indeed have the same features with mechanical types but with a difference which they have a hydraulic booster to facilitate the rotation of steering wheel. Beside advantages in hydraulic systems, they are some disadvantages in this system that one of the most important of them is reducing the output power of engine. To restore this power dissipated, we use ESP systems. In this article output diagrams given by software, are showing that IKCO SAMAND vehicle which equipped with ESP system, exerts less torque and power on steering wheel. This improves the safety of driver and also performance of the vehicle at high speeds and reduces fuel consumption beside increasing the efficiency of IC engine.