The optical crosstalk between the pixel units can influence the image quality of CMOS image sensor. In the meantime, the duty ratio of CMOS is low because of its pixel structure. These two factors cause the low detection sensitivity of CMOS. In order to reduce the optical crosstalk and improve the fill factor of CMOS image sensor, a microlens array has been designed and integrated with CMOS. The initial parameters of the microlens array have been calculated according to the structure of a CMOS. Then the parameters have been optimized by using ZEMAX and the microlens arrays with different substrate thicknesses have been compared. The results show that in order to obtain the best imaging quality, when the effect of optical crosstalk for CMOS is the minimum, the best distance between microlens array and CMOS is about 19.3 μm. When incident light successively passes through microlens array and the distance, obtaining the minimum facula is around 0.347 um in the active area. In addition, when the incident angle of the light is 0^o~22^o, the microlens array has obvious inhibitory effect on the optical crosstalk. And the anti-crosstalk distance between microlens array and CMOS is 0 μm~162 μm.

A polymer-based multimode interference (MMI) optical splitter chip has been fabricated through UV-based soft imprint lithography (Soft UV-NIL) technique. Propagation loss and bending loss are considered during the chip design in order to decrease the insertion loss. UV curable fluorinated acrylate resin is used due to its low material absorbing loss. 1×4 cascaded MMI splitter is fabricated and measured at 1550 nm optical wavelength and an average 12.38 dB insertion loss is obtained together with an 1.23 dB uniformity.

Cross-sensitivity is a crucial parameter since it detrimentally affect the performance of an accelerometer, especially for a high resolution accelerometer. In this paper, a suite of analytical and finite-elements-method (FEM) models for characterizing the mechanism and features of the cross-sensitivity of a single-axis MOEMS accelerometer composed of a diffraction grating and a micromachined mechanical sensing chip are presented, which have not been systematically investigated yet. The mechanism and phenomena of the cross-sensitivity of this type MOEMS accelerometer based on diffraction grating differ quite a lot from the traditional ones owing to the identical sensing principle. By analyzing the models, some ameliorations and the modified design are put forward to suppress the cross-sensitivity. The modified design, achieved by double sides etching on a specific double-substrate-layer silicon-on-insulator (SOI) wafer, is validated to have a far smaller cross-sensitivity compared with the design previously reported in the literature. Moreover, this design can suppress the cross-sensitivity dramatically without compromising the acceleration sensitivity and resolution.

Dimensional metrology for micro structure plays an important role in addressing quality issues and observing the performance of micro-fabricated products. Different from the traditional white-light interferometry approach, the modulation-based method is expected to measure topography of micro structure by the obtained modulation of each interferometry image. Through seeking the maximum modulation of every pixel respectively in Z direction, the method could obtain the corresponding height of individual pixel and finally get topography of the structure. Owing to the characteristic of modulation, the proposed method which is not influenced by the change of background light intensity caused by instable light source and different reflection index of the structure could be widely applied with high stability. The paper both illustrates the principle of this novel method and conducts the experiment to verify the feasibility.

White-light scanning interferometry plays an important role in precise profile metrology of microstructure. However, applying this approach may also be limited because of the optical reflection behavior of the surface. While there is a thin film on the surface, the reflection behavior of top and bottom of the thin-film will cause severer phase errors. Recently, the method by combining both reflectometry and white-light scanning interferometry is proposed to measure the film thickness and surface profile. This article firstly explains the principle of the proposed method and then verifies the feasibility of the thickness-measurement method for transparent film on a Silicon surface. Both of the algorithm and the experiment system have been optimized to measure the film thickness with high precision.

For the far distance and weak signal detecting, low background noise is essential. Because the spatial noise of infrared system is mostly determined by spontaneous thermal radiation, it is the most directly method to achieve low spatial noise by refrigerating optics. This paper introduced a low radiation optical system with lens positioned inside of the infrared detector Dewar. The system includes two parts: the two mirror Cassegrain system working at room temperature which images the intermediate focus (IF) and the lens positioned inside of infrared detector Dewar which image the IF to focal plane. The working temperature inside of the infrared detector Dewar is 80K, the cryogenic lens contain three pieces lens whose total weight is below 5g. In view of engineering application, the low radiation optical system, the stray light analysis, cryogenic optics mounting and system testing were discussed. Calculations indicate that the equivalent blackbody radiation temperature (EBRT) is less than 180K.

Optical micro-structure array, including microlens array and pyramid array, has the function of integral imaging or diffraction beam-splitting. Careful measurement of the 3D profile of the array is a basic approach for insuring its quality. However, due to the limited numerical aperture of microscopy, when the surface is too steep, typically larger than 45 degrees, little light will be reflected or scattered back to the measurement equipment. The signal-to-noise-ratio will drop below the measurable threshold and information will be lost during measurement. In our case, the dihedral of the sample surface is 90 degrees. Intuitively, the reflected rays should be parallel to the incident rays after twice reflection and can be picked up by the detector. Nevertheless, the white-light interference microscope still showed no information on the 45- degree-inclined surface. In this paper, we study the twice-reflection of the dihedral angle of 90 degrees. We put it in the test beam of a spherical interferometer to simulate the situation in microscope. Simulation and real experiments suggest that the twice-reflection beam is of low spatial coherence and may act as the background intensity in white-light interferogram. This result cannot lead to a novel testing approach directly but points out the problem. We will sprout new idea based on it.

Hydrostatic guideway has been widely used for ultra-precision machine tools due to its high stiffness and motion accuracy. In order to optimize the stiffness and motion accuracy of hydrostatic guideway, the effect of different diameters orifice restrictors on the stiffness and deformation of hydrostatic guideway is investigated in detail in this paper. The theoretically optimal structural coefficient is verified through the experiments. Hydrostatic guideway can obtain the maximum stiffness when the value of optimal structural coefficient is 0.707. And changing the diameter of orifice restrictors is an effective method to adjusting the structural coefficient. Due to the error caused by manufacture and assembly of hydrostatic guideway, the optimal structural coefficient is hard to be obtained accurately. Based on this condition, a larger structural coefficient is adopted to reduce the oil pressure in the pocket of hydrostatic guideway effectively, so that the deformation of guideway can be reduced. And finally, the stiffness loss caused by the deformation decreased. In addition, the experimental results show that the maximum deformation of hydrostatic guideway can be reduced from 2.06μm to 1.82μm and the stiffness arise from 1453N/μm to 1855N/μm when orifice restrictors with 0.15mm diameter are used rather than 0.2mm diameter.

Optical assembly and alignment system plays a crucial role for the construction of high-power or high-energy laser facility, which attempts to ignite fusion reaction and go further to make fusion energy usable. In the optical assembly and alignment system, the vibration control is a key problem needs to be well handled and a material with higher damping performance is much desirable. Recently, a new kind of smart magneto-sensitive polymeric composite material, named magnetorheological plastomer (MRP), was synthesized and reported as a high-performance magnetorheological material and this material has a magneto-enhanced high-damping performance. The MRP behaves usually in an intermediate state between fluid-like magnetorheological fluid and solid-like magnetorheological elastomer. The state of MRP, as well as the damping performance of MRP, can be tuned by adjusting the ratio of hard segments and soft segments, which are ingredients to synthesize the polymeric matrix. In this work, a series of MRP are prepared by dispersing micron-sized, magneto-sensitive carbonyl iron powders with related additives into polyurethane-based, magnetically insensitive matrix. It is found that the damping performance of MRP depends much on magnetic strength, shear rate, carbonyl iron content and shear strain amplitude. Especially, the damping capacity of MRP can be tuned in a large range by adjusting external magnetic field. It is promising that the MRP will have much application in passive and active vibration control, such as vibration reduction in optical assembly and alignment system, vibration isolation or absorption in vehicle suspension system, etc.

With the gradual development of micro-satellite technology and the extension of application field of earth observation technology, researchers show more concern and attention on how to obtain high-resolution images with microsatellite platform equipped with space telescope. Such microsatellites require the space telescopes with small volume, low mass, and low cost. Deployable telescope is a good choice to meet these requirements, and it has the same capabilities as the traditional space telescope. We investigate a space telescope with smart self-deployable structure. The telescope is folded before launch, the distance between primary mirror and secondary mirror becomes short and the volume of the telescope becomes small, and the telescope extends to its working configuration after it is in orbit. The deployable structure is one of the key techniques of deployable space telescope, and this paper focuses on the design of a self-deployable structure of the secondary mirror. There are mainly three parts in this paper. Firstly, the optics of the telescope is presented, and a Ritchey-Chretien (RC) type optical system is designed. Secondly, the self-deployable structure is designed and the finite element method (FEM) is used to analyze dynamics of the extended telescope. Thirdly, an adjusting mechanism with six degrees of freedom to correct the misalignment of the secondary mirror is investigated, and the kinematics is discussed.

For the purpose of investigating possibilities of utilizing, for sensing application, changes in speckle patterns to be observed in an output light spot from an optical fiber due to external disturbance, a certain level of load was applied onto an optical fiber through which laser beams emitted from a laser diode were propagating, and changes in the speckle patterns in the output light spot were investigated. In order to realize effective load application onto the optical fiber, a load application section was provided in which several ridges were intentionally provided onto opposite flat plates. A jacket-covered communication-grade multi-mode glass optical fiber was placed in the load application section so that corrugated bending of the fiber was intentionally induced via load application due to the ridges. A PV cell panel was irradiated with the output light spot from the optical fiber containing the speckle patterns therein. When weights were placed in the load application section, an output voltage from the PV cell panel was changed, indicating that the load application onto the optical fiber can be detected with this detection setup. Removal of the once-placed weights was also detected via changes in the PV cell panel output. Then, the load application onto the optical fiber and its removal was successfully detected via turn-on/off operations of an LED which was controlled in accordance with the changes in the output voltage level from the PV cell panel, in other words, through the changes in the speckle patterns.

The design and preparation of an ultrathin dual-band metamaterial absorber whose resonant frequency located at radar wave (20 GHz-60 GHz) is presented in this paper. The absorber is composed of a 2-D periodic sandwich featured with two concentric annuluses. The influence on the absorber’s performance produced by resonant cell’s structure size and material parameters was numerically simulated and analyzed based on the standard full wave finite integration technology in CST. Laser ablation process was adopted to prepare the designed absorber on epoxy resin board coated with on double plane of copper with a thickness that is 1/30 and 1/50 of the resonant wavelength at a resonant frequency of 30.51 GHz and 48.15 GHz. The full width at half maximum (FWHM) reached 2.2 GHz and 2.35 GHz and the peak of the absorptance reached 99.977%. The ultrathin absorber is nearly omnidirectional for all polarizations. The test results of prepared sample testify the designed absorber’s excellent absorbing performance forcefully. The absorber expands inspirations of radar stealth in military domain due to its flexible design, cost-effective and other outstanding properties.

We propose a new scheme of lasing in a nano-grating with Fano resonance by the independent control of dark and bright modes. The controllability of both dark and bright modes can be achieved by fine-tuning the widths of two kinds of metallic stripes in the nano-grating. It enables the match between resonant frequencies of the nano-grating structure and the absorption and emission frequencies of gain medium. For example, changing the width of the thin strip is to hit the emission peak of the gain medium, while the fat strip corresponds to the absorption peak of the gain medium. We work out an optimal example of silver grating immersing Rhodamine dye, verifying the lasing dynamic process with minimum threshold and maximum output power. It may provide a new way on low-threshold and high-efficient plasmon laser.

We design and fabricate a broadband micro polarization beam splitter on SOI (Silicon-On-Insulator) substrate which is compatible with the 180 nm COMS process. The polarization splitter is based on mismatch coupling in which a tapered directional coupler structure with slowly varying waveguide width is used. The device is fabricated in Astar-IME silicon photonics platform. When the waveguide width of the wider port of the tapered waveguide is fixed at 550 nm, by sweeping the taper waveguide length in several waveguide width of the narrower port, the polarization splitter can realize high extinction ratios of the both polarizations in a broad wavelength range. When the waveguide width of the narrow port is 410 nm, the device can split the TE and TM polarizations in a 30 μm length with the extinction ratios of the both polarizations more than 15 dB over a wavelength range from 1500 nm to 1600 nm. The proposed polarization beam splitter is not sensitive to the fabrication error and has large tolerance. The polarization extinction ratios are still more than 10 dB in a wavelength range of 100 nm even if the waveguide width of the taper has a 50 nm fabrication error. Due to its simple structure and high performance, we believe this micro polarization beam splitter will be widely used in photonic integrated circuit, optical signal processing, and optical communication devices.

Emerging applications in communication, sensing, medical, and many other fields call for on-chip microring laser, however, the method to make it work at mid-infrared still need to be explored. In this paper, a microring resonator integrated in flexible substrate is designed and evaluated, with high Q-factor (~10⁵) at pump and signal wavelengths, achieving emission in mid-infrared (3.6μm) using rare earth doped chalcogenide glass. Furthermore, the strain-optical coupling in multilayer flexible materials is numerically verified, and a 0.3 nm/με resonance wavelength shift is achieved by local neutral axis theory, without significant loss of flexible device performance.

With the development of optical technology, optical instruments become smaller and more integrated. Because of the high diffraction efficiency and light weight, binary optical elements become more and more popular. Binary optical elements can only blaze at one wavelength, it has high diffraction efficiency at design wavelength. But the diffraction efficiency of binary optical elements will decrease quickly with the change of wavelength. And this situation will have a big impact on image quality. Since double-layer BOE can blaze at two wavelengths, it has high diffraction efficiency at wide spectral bandwidth. There are kinds of fabrication errors. Based on scalar diffraction theory, this paper analyzes the diffraction efficiency of double-layer BOE with fabrication errors and simulates it in MATLAB. Simulation shows the diffraction efficiency decreases quickly if the depth errors of two layers are opposite, and this situation should be avoided. As for periodic errors, tilt errors and angular errors, these fabrication errors have different impact of double-layer BOE on diffraction efficiency.

X-ray MicroandNano imaging is developed based on the conventional x–ray tomography, it can not only provide nondestructive testing with higher resolution measurement, but also be used to examine the material or the structure with low atomic number and low density. The source with micro-focal spot size is one of the key components of x-ray MicroandNano imaging. The focused electron beam from SEM bombarding the metal target can generate x-ray with ultra-small size. It is convenient to set up x-ray microscopy based on SEM for laboratory use. This paper describes a new x-ray microscopy using reflection targets based on FEI Quanta600 SEM with tungsten filament. The flat panel detector is placed outside of the vacuum chamber with 300μm thickness Be-window to isolate vacuum from the air. A stage with 3 DOFs is added to adjust the positions of the target, the SEM’s sample stage is used to move sample. And the shape of target is designed as cone with 60° half cone angle to get the maximum x-ray dosage. The attenuation coefficient of Bewindow for x-ray is about 25%. Finally, the line pair card is used to evaluate the resolution and the result shows that the resolution of the system can receive less than 750nm, when the acceleration voltage is 30keV, the beam current is 160nA, the SEM working distance is 5mm and the acquisition time of the detector is 60s.

A microfocus electron-impact X-ray source with micro-beam was introduced in this paper. The tungsten cathode electrogun is used as emitting system, and the focusing system is consists of two magnetic solenoid lenses, it is effective, light and handy. The matching problems between emitting system focusing system are studied on the microfocus X-ray source. The current of the first focusing lens and the second focusing lens is 0.8A and 1.64A at the voltage of 90kV respectively, and the filament current is 2.5A. Under the condition, the micro-beam spot X-ray is gained. The test results of stability showed that the X-ray source have a excellent stability, X-ray intensity of which is 110.6±0.03μSr/hr, target current of which is 185.5±1.5μA, and the target temperature of which is 96.5±0.5°C.The resolution of micro-focus X-ray source is about 4μm by the analysis of JIMA, which meet the application requirement of microfocus X-ray source.

In this paper, we propose and demonstrate numerically a pixelated component for full Stokes polarization imaging by integrating linear polarizers and circular polarizers on a single silicon chip working in near infrared band (~1.6μm). The micro linear polarizers collect linear polarizing information from different orientations while the circular polarizers collect left-handed or right-handed circular polarization information such that full Stokes polarization imaging can be implemented on a single chip in real time. Numerical results show that the extinction ratio and TM transmission of linearly polarization can reach 45dB and 78%, respectively, with a linear metallic grating of period 300nm, and the dichroism of left-handed and right-handed circular polarization can reach 55% with a plasmonic chiral structure that is compatible with linear gratings in terms of structure and fabrication. The proposed structure is of significance in real-time full Stokes polarization imaging.

Aiming at the high precision and efficiency requirements of Z-direction locating in Talbot lithography, a control system based on Voice Coil Motor (VCM) was designed. In this paper, we built a math model of VCM and its moving characteristic was analyzed. A double-closed loop control strategy including position loop and current loop were accomplished. The current loop was implemented by driver, in order to achieve the rapid follow of the system current. The position loop was completed by the digital signal processor (DSP) and the position feedback was achieved by high precision linear scales. Feed forward control and position feedback Proportion Integration Differentiation (PID) control were applied in order to compensate for dynamic lag and improve the response speed of the system. And the high precision and efficiency of the system were verified by simulation and experiments. The results demonstrated that the performance of Z-direction gantry was obviously improved, having high precision, quick responses, strong real-time and easily to expend for higher precision.

The spectrum-integral Talbot lithography (STIL) was introduced into the fabrication of one-dimensional micro gratings using the broad-band UV illumination in this paper. In the process of spectrum-integral Talbot lithography, the self-images and π-phase-shifted images generated by different wave lengths overlap and integrate collectively to enormously extend the continuous depth-of-focus area since a certain distance away from the mask. As a result, the route of STIL proves to be of great potential for periodic frequency-doubling in good contrast without any complex improvement and operation to the traditional proximity lithographic system of UV mask aligner.

In the process of actual measurement and analysis of micro near infrared spectrometer, genetic algorithm is used to select the wavelengths and then partial least square method is used for modeling and analyzing. Because genetic algorithm has the disadvantages of slow convergence and difficult parameter setting, and partial least square method in dealing with nonlinear data is far from being satisfactory, the practical application effect of partial least square method based on genetic algorithm is severely affected negatively. The paper introduces the fundamental principles of particle swarm optimization and support vector machine, and proposes a support vector machine method based on particle swarm optimization. The method can overcome the disadvantage of partial least squares method based on genetic algorithm to a certain extent. Finally, the method is tested by an example, and the results show that the method is effective.

An electro-wetting-based variable-focus liquid lens with a spin coated polydimethylsiloxane (PDMS) layer is presented. The PDMS layer acts as both insulation and hydrophobic material of the liquid lens. By changing the applied voltage between the two electrodes, the radius of the water-oil contact curved surface is adjusted to realize the zoom function. In preparation process, at first, the liquid lens is divided into two parts, the PDMS substrate and the cavity, and then two parts of liquid lens are bonding together after surface treatment. After liquid injection and sealing cavity, the whole process was accomplished. The zooming performance of lens is tested, and COMSOL is used to analyze the shape of the water-oil contact curved surface at different voltages, the results shows that with the applied voltage changing from 0V to 120V, the height of meniscus vertex reduced from 2.41mm to 1.67mm, and the focal length changes from -14.3mm to infinity first, and then to 27.1mm.

With the advantages of small structure and high efficiency, the diffractive element is widely used in the construction of a structured light 3D measurement system. But the working wavelength of diffraction element is single, and the light field generated by the diffraction element is only one channel. We make the original single channel into three channels, so as to achieve from the serial algorithm to parallel algorithm to improve the measurement speed. Based on the lattice light field and the design method of multi wavelength diffraction elements, and in the premise of ensuring the number of points, the traditional lattice points of light field are divided into three channels. These channels are regarded as the target fields, and the diffraction element for generating color structure light field is designed.

According to the exposure pattern distortion in contact printing caused by the photoresist and sometimes has a rough surface with impurity particles on it, we propose a new flexible hybrid mask for contact printing. The mask consists of three layers: a flexible polymer buffer layer, a polymer structure layer of high Young's modulus, and a metal masking layer. Because the hybrid mask skillfully combines the characteristics of flexible polymer and high Young's modulus polymer, it has two advantages: high flexibility and high resolution. The flexible hybrid mask can attach closely with the photoresist under the condition of vacuum adsorption. So the fabrication of micro-nano structures with high precision and high resolution can be realized. In this paper, a new flexible hybrid mask with critical dimension of 2um was fabricated. The photoresist structure with high precision was manufactured using this mask by photolithography and it verified the feasibility of the mask for lithography.

With the raising requirements in micro optical systems, the available machines become hard to achieve the process dynamic and accuracy in all aspects. This makes compact design based on fluid/structure interactions (FSI) important. However, there is a difficulty in studying FSI with oil film as fluid domain. This paper aims at static characteristic design of a hydrostatic guide-way with capillary restrictors based on FSI. The pressure distribution of the oil film land is calculated by solving the Reynolds-equation with Galerkin technique. The deformation of structure is calculated by commercial FEM software, MSC. Nastran. A matlab program is designed to realize the coupling progress by modifying the load boundary in the submitting file and reading the deformation result. It’s obvious that the stiffness of the hydrostatic bearing decreases with the weakening of the bearing structure. This program is proposed to make more precise prediction of bearing stiffness.

At present, the splitting ratio test of the waveguide coupler usually adopts optical fiber coupling test method. The coupling process is complex and the coupling loss is different in two pigtail fibers, what can result in error in the splitting ratio. A new method for testing the splitting ratio of waveguide coupler using laser beam profiler is presented. Laser beam profiler is used to scan the horizontal directional light field in the cross-section of the waveguide. The measurement data are obtained. Data fitting and processing is carried out by data processing program. Finally, two light field curves are gotten, and the splitting ratio of the waveguide coupler is calculated. The feasibility of the new method is verified using fiber coupler. The error using the new method is only 0.68%. The waveguide coupler testing platform is built. The relationship between the measurement range of the splitting ratio and the minimum distances of the waveguide coupler is analyzed. The research provides an effective and convenient method for the test of splitting ratio of waveguide coupler.

Three-dimensional wafer stage is an important component of lithography. It is required to high positioning precision and efficiency. The closed-loop positioning control system, that consists of five-phase step motor and grating scale, implements rapid and precision positioning control of the three-dimensional wafer stage. The MCU STC15W4K32S4, which is possession of six independent PWM output channels and the pulse width, period is adjustable, is used to control the three axes. The stepper motor driver and grating scale are subdivided according to the precision of lithography, and grating scale data is transmitted to the computer for display in real time via USB communication. According to the lithography material, mask parameter, incident light intensity, it's able to calculate the speed of Z axis, and then get the value of PWM period based on the mathematical formula of speed and pulse period, finally realize high precision control. Experiments show that the positioning control system of three-dimensional wafer stage can meet the requirement of lithography, the closed-loop system is high stability and precision, strong practicability.

Optical design of a novel optical imaging system is presented. It can overcome the scaling of the aberrations by dividing the imaging task between a single objective lens that achieves a partially corrected intermediate image on a spherical surface, and an array of micro-lens, each of which relays a small portion of the intermediate image to its respective sensor, correcting the residual aberrations. The system is aimed for obtaining large field-of-view without deteriorating its resolution, of which traditionally designed optical imaging systems have met great difficult. This progress not only breaks through the traditional restrictions, but also allows a wider application for optical imaging systems. Firstly, proper configuration, which satisfies both the requirement of compactness and high performance, is determined according to the working principle of the novel system and through the research of the design idea in this paper. Then, a design example is presented with the field-of-view 50°and its resolution 0.2mrad, which remains as the field-of-view scales. But the optimized scalable system is of close packed structure and its dimension is less than 300mm along the ray incidence.

Because industry demand for LED,LCD panel continues to increase, the high yield of micron-scale resolution lithography is increasingly prominent for manufacturers, which requires the field of lithography objective lens becomes larger. This paper designed a lithography lens with large field, whose effective image side field will reach to 132 × 132mm.Subsequently, the tolerance was analysed by simulation for the optical system. Finally, it is proved that the design meets the requirements of micron-scale resolution.

To overcome the disadvantages of high-cost, low-efficiency and the difficulty in the realization of the high aspect ratio structure in the fabrication of nanoimprint mold with deep-subwavelength structures by electron beam lithography (EBL), the holographic immersion lithography - ion beam etching is adopted. There are two major challenges of this method: the holographic immersion lithography and the ion beam etching. The former one is to fabricate the photoresist mask with deep-subwavelength structures; and the latter one is to transfer the photoresist mask to the fused silica. Both the two steps have been optimized to achieve the accurate control of the high aspect ratio of the profile. The experiment indicates that titled rotation of the ion beam etching combined with reactive ion beam etching can achieve the accurate control of the high aspect ratio structure. The nanoimprint mold with the period of 180nm and the groove depth of 233nm has been fabricated.

In this paper, we present an optical maskless exposure approach for direct patterning of large-area high resolution microfluidic chips using photosensitive poly(dimethylsiloxane) (PDMS) materials. Both positive- and negative-tone photosensitive PDMS (photoPDMS) were successfully patterned into various microfluidic devices with complex geometries by using an optical maskless lithography process. The positive-tone PDMS is used for patterning of largearea chips, while the negative-tone PDMS is demonstrated to fabricate high-resolution microstructures and on-chip devices. With the seamless pattern-stitching technique, a large-area microfluidic chip with size of 5.5 × 2.8 cm² with complex three-dimensional (3D) staggered herringbone mixers (SHMs) for micro-flow gradient generation has been directly fabricated within 125 minutes by using the positive-tone PDMS. A small microfluidic chip with feature size as small as 5 μm is demonstrated by using the negative-tone PDMS. The experimental results reveal that the optical maskless lithography technology enables to rapidly pattern high-resolution microstructures and is very promising for development of lab-on-a-chip devices.

Proposing a new method for testing the ultra-precision aerostatic spindle motion accuracy based on analyzing the online real-time dynamic interference image. Optical flat crystal as the testing standard will be installed at the end of the ultra precision aerostatic spindle and will motion along with the spindle. On the other end of the spindle, the tool will be installed for online processing. The image data of optical flat crystal collected by the high-precision dynamic interferometer will be processed for analyzing the spindle error. For collecting higher accuracy image data, the installation way of optical flat crystal is one of the key technologies. Base on this, the effects of the clamping means on the surface accuracy of optical flat crystal is studied. At first, the finite element model of the optical flat crystal`s clamping structure were established. Secondly, the influence of the material of the supporting annulus, preload lateral clamping and spindle speed on the surface accuracy of optical flat crystal had been analyzed. At last, the improved and optimized structure of the optical flat crystal has been presented. As the analysis results shown, the RMS value of reference surface is 9.47nm and the deformation values of the central region is 0.17nm which satisfies the requirement of surface accuracy and installation of optical flat crystal. It has a very important theoretical and practical significance to establish spindle online testing system and research rotary error generating mechanism of ultra-precision spindle to improve surface accuracy of ultra-precision machining.

Social order is threatened by counterfeit money. Conventional anti-counterfeit technology is much too old to identify its authenticity or not. The intrinsic difference between genuine notes and counterfeit notes is its paper tissue. In this paper a new technology of detecting RMB is introduced, the polarization parameter indirect microscopic imaging technique. A conventional reflection microscopic system is used as the basic optical system, and inserting into it with polarization-modulation mechanics. The near-field structural characteristics can be delivered by optical wave and material coupling. According to coupling and conduction physics, calculate the changes of optical wave parameters, then get the curves of the intensity of the image. By analyzing near-field polarization parameters in nanoscale, finally calculate indirect polarization parameter imaging of the fiber of the paper tissue in order to identify its authenticity.

In the field of telescope applications, it needs to adjust the focus to get clearer image of objects at different distance. Novel design of focus adjusting apparatus with long journey is presented here. This apparatus has long journey of second mirror extended to 20mm. And its adjusting precision is about 0.1μm. This apparatus can be controlled with two modes. One mode is manual control. The other mode is automatic control. The design can be applied to the fields of telescopes which needs long adjusting range and high precision.

Carbon fiber composite is widely applied to the field of aerospace engineering because of its excellent performance. But it will be able to form more defects in the process of manufacturing inevitably on account of unique manufacturing process. Meanwhile it has sophisticated structure and services in the bad environment long time. The existence of defects will be able to cause the sharp decline in component’s performance when the defect accumulates to a certain degree. So the reliability and safety test demand of carbon fiber composite is higher and higher. Ultrasonic testing technology is the important means used for characteristics of component inspection of composite materials. Ultrasonic information detection uses acoustic transducer generally. It need coupling agent and is higher demand for the surface of sample. It has narrow frequency band and low test precision. The extrinsic type optical fiber F-P interference cavity structure is designed to this problem. Its optical interference model is studied. The initial length of F-P cavity is designed. The realtime online detection system of carbon fiber composite is established based on optical fiber F-P Ultrasound sensing technology. Finally, the testing experiment study is conducted. The results show that the system can realize real-time online detection of carbon fiber composite’s defect effectively. It operates simply and realizes easily. It has low cost and is easy to practical engineering.

Metal materials have been used in aerospace and other industrial fields widely because of its excellent characteristics, so its internal defects detection is very important. Ultrasound technology is used widely in the fields of nondestructive detection because of its excellent characteristic. But the conventional detection instrument for ultrasound, which has shortcomings such as low intelligent level and long development cycles, limits its development. In this paper, the theory of ultrasound detection is analyzed. A computational method of the defects distributional position is given. The non-contact type optical fiber F-P interference cavity structure is designed and the length of origin cavity is given. The real-time on-line ultrasound detecting experiment devices for internal defects of metal materials is established based on the optical fiber F-P sensing system. The virtual instrument of automation ultrasound detection internal defects is developed based on LabVIEW software and the experimental study is carried out. The results show that this system can be used in internal defect real-time on-line locating of engineering structures effectively. This system has higher measurement precision. Relative error is 6.7%. It can be met the requirement of engineering practice. The system is characterized by simple operation, easy realization. The software has a friendly interface, good expansibility, and high intelligent level.

In this paper, a new type of lightweight passive deployment mechanism based on the tape spring and the shape memory alloy is presented for the secondary mirror of a deployable space telescope. In this passive deployment mechanism for the secondary mirror, the high elastic potential energy of the folded tape springs is used as driving force when the support structure is extended, and the high stiffness characteristics of the circular arc cross section of the tape spring can be used to achieve structure self-locking after deployment. Then a deployable space telescope combined with lightweight passive deployable mechanism for the secondary mirror is designed for applying to nanosatellite imaging. Furthermore, a lock-release device is designed to achieve the function of locking the folded structure and releasing on orbit by taking advantage of the phase transformation characteristics of shape memory alloy with temperature changing. Finally, the correction method for the deployment error of secondary mirror is discussed. The temperature of the tape springs is controlled respectively to make a required length change. This can achieve the purpose of adjusting the position of the secondary mirror and improve the deployment accuracy.

Surface-Enhanced Raman Scattering (SERS) is a powerful spectroscopic technique for highly sensitive molecular detection. It effectively improves the defect of low sensitivity of normal Raman spectra. So it is widely used in the area of surface science, analytical science, biological science and so on. Using Density Functional Theory (DFT) and Time- Dependent density functional theory (TD-DFT), the SERS spectrum has been simulated for biphenyl l-4, 4′-dithiol (BPDT, HS-(C₆H₄)₂-SH), p-terphenyl-4, 4″-dithiol (TPDT, HS - (C₆H₄)₃-SH )1, 4-benzenedithiol (BDT) absorbed on AuNPs and AgNPs. The SERS which aroused by C-C stretching mode is increasing with the benzene ring. Whereas, for the SERS of S-H bending vibrational mode, changing the position of S atom have little effect. The C-S stretching mode and S-H stretching mode are also little effect by the insert number.

A novel fiber relative humidity (RH) sensor is demonstrated in this paper. The sensor is composed of a fiber Michelson modal interferometer (MMI) and the ZnO nanorods which grown on the fiber to improve the sensitivity of the sensor. Two standard single mode fibers are spliced to form the MMI, misaligned splicing program is used at the spliced point. Relative humidity sensing experiment shows that the intensity of interference spectrum changes linearly with relative humidity. With the relative humidity increasing in the range from 30% to 85%, the intensity of the dip in the interference spectrum linearly increases higher than 50%. The relative humidity response of the sensor is induced by the interference between core mode and cladding mode. The ZnO nanorods with high surface to volume ratio grown outside of the fiber cladding enhance the sensitivity of the sensor.

We report a high-sensitivity refractive index sensor based on microfiber long period gratings (MLPGs) fabricated by a CO₂ laser line-by-line inscription. The microfiber was fabricated by using hydrofluoric acid (HF) to etch a conventional single mode fiber (SMF). The MLPGs were fabricated by periodically tapering the microfiber with CO₂-laser pulse line by line. We showed that a 45-period long period grating with about 15 dB attenuation dip can be realized in the microfiber with a diameter of ~32μm. The MLPGs were found to have a very high sensitivity to external refractive index, in which the sensitivity of the MLPGs can be 4 times than that of a normal long period grating (LPG).

The configurations of nuclei in Au catalyzed Si nanowire growth were investigated through an ab-initio thermodynamic-combined approach. We discussed the relation between the configurations and formation energies of the lateral walls of the nucleus in nanowire growth numerically by the classical nucleation theory. The nucleation model was parameterized by the formation energies of surfaces, interfaces and steps calculated in first-principles methods. The configurations of the nuclei were determined by the Wulff theorem. Moreover, we found configurations of the nuclei are different in two different Si-Au contact structures. This study provides an important basis to understand the step-flow process in nanowire growth.