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- Front Matter: Volume 9686
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Front Matter: Volume 9686
Front Matter: Volume 9686
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This PDF file contains the front matter associated with SPIE Proceedings Volume 9686, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and Conference Committee listing.
Oral Session
Imaging technique based on multilinear array integrated TDICCD
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This paper introduces the multi-linear array integrated TDICCD image sensor, analyses the characteristic of drives based on this type of image sensor, lists several different driving schemes, uses FPGA as hardware platform, and designs each driving timing program of multi-linear array integrated TDICCD with VHDL. The optimal program not only can generate correct timing which drives image sensor working normally, but shifts all the pixels of both panchromatic and multi-spectral bands at the same frequency in the same integration time, efficiently avoids the imaging interferences among different linear arrays, improves the image quality. Through simulation and actual imaging test, the driving timing designed is proved to meet the requirements of sensor work. At present, the design has been run in orbit correctly and stably, already gained high quality remote sensing images.
THz transmittance and electrical properties of silicon doped vanadium dioxide films tuning by annealing temperature
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Silicon doped vanadium dioxide (VO2) films were successfully prepared on high purity Si(111) substrate. Confirmed by X-ray diffraction, all samples showed a preference orientation of (011) direction. Introducing silicon led grain sizes decreasing comparing to undoped VO2 film, and this result induced a narrow hysteresis width in MIT performance. Furthermore, silicon doped VO2 films annealing in different temperature presented different phase transition properties. In the electrical, a higher annealing temperature resulted in a decrease of sheet resistance and lowering the transition temperature. In terahertz optical transmittance, silicon doped VO2 films keep an excellent modulation ratio, indicating a great potential in the application of terahertz modulator devices.
Research of timing design and adjusting methods of EMCCD
Wang Peng,
ZhiKuan He,
Liu Qi
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With development of low light level detection technologies, imaging systems based on EMCCD are widely applied. Timing design of EMCCD is one of the key factors for the imaging systems’ designs. Considering with the electronic characteristics of EMCCD, timing design of one EMCCD imaging system is studied in this paper. Based on several solutions of EMCCD timing designs, influences of EMCCD’s timing digital signals to imaging analog signals were observed and a timing adjusting method was found out. Simulation and test results of the proposed prototype shows that a signal adjusting phase precision of one degree is achieved at room temperature, and optimization of the timing signals has been implemented thereby improving imaging quality of the EMCCD’s imaging system.
A deformable plane-parallel optical plate with 16 actuated points for low order aberrations correction
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Since the microlithography with high number aperture(NA) projection objectives requires the correction of thermal lens aberrations, a deformable plane-parallel optical plate with continuous facesheet, 16 discrete actuators has been designed from the elasticity theory. Both axial forces and tangential bending moments are applied to the discrete position outside the clear aperture. The deformable plate needs to meet the condition that each actuator can generate a positive or a negative axial force. The deformable plate has been simulated by finite element modeling (FEM), the results show that the difference between the simulation force and the theory force is always less than 0.064N when the deformation is one of Z4-8 low order Zernike modes with 100nm coefficient, the axial forces are minor and the fitting errors of the aberrations are less than 5%.
Optimizing design method of static simulation for Unimorph DM
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Single layer piezoelectric driving deformable mirror (Unimorph DM) with large deformation, simple fabrication process and low cost has been widely applied for the adaptive optics system in recent years. In the past, the optimal design of deformable mirror is often used in analytic method, and made much simplified approximation in theory. This results in large error between theoretic and real system. In this paper, the influence laws between the fitting error and the effective aperture, and the spatial distribution are studied by the dynamic–electricity coupling simulation method. The relationship between the displacement and the thickness of the mirror, the diameter and thickness of the electrode and the width of the support ring are discussed. According to these rules, a scheme of optimizing the structure of deformable mirror has been proposed, and the key parameters are designed according to the requirements of the retinal imaging system. In the end, all the fitting errors of former Zernike items 3-30 are less than 0.4 with the rated voltage of 400V.
A novel CPPM anti-crosstalk collision avoidance lidar with ultra-low laser power
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In this paper, we demonstrate a novel concept of collision avoidance based on single photon detectors along with time correlated single photon counting techniques, which uses chaotic pulse position modulation for anti-crosstalk considerations. In order to distract the signal from estimated background noise, parameters including pulse rate, discrimination threshold and number of accumulated pulses have been thoroughly analyzed based on the detection requirements, resulting in specified receiver operating characteristics curves. Both simulation and indoor experiments were performed to verify the excellent anti-crosstalk capability of the presented collision avoidance LIDAR despite of ultra-low transmitting power.
High performance organic optoelectronic integrated device based on thermally activated delayed fluorescence material with an interlaid architecture
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A high performance organic integrated device (OID) has been realized with a thermally activated delayed fluorescence (TADF) material namely, 4,5-bis(carbazol-9-yl)-1,2-dicyanobenzene (2CzPN) and another transport material named 4,7-diphenyl-1, 10-Phenanthroline (Bphen) with an interbedded architecture as the active layer. The OID had a high detectivity of 0.8×1012 Jones at -1 V under the UV-365 nm illumination with an intensity of 0.2 mW/cm2, and yielded an exciplex EL light emission with a maximum luminance of ~12000 cd/m2. While the non-intebedded device has a detectivity of 4.1×1010 Jones and a maximum luminance of 8300 cd/m2.
Simulation of GaN/InGaN avalanche phototransistors
Zhongliang Zhou,
Min Zhu,
Qi Wu,
et al.
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Physical simulation of a two-terminal typical avalanche phototransistor with a floating base (2T-APT) based on GaN/InGaN is reported. The simulated current characteristic is also compared with the experiment result. Under high voltages, the carriers multiply in the reverse-biased base-to-collector (BC) junction. To reduce the avalanche breakdown voltage, the doping concentration and the thickness of the base are discussed in detail. It is found that the lower voltage could be achieved by decreasing the doping concentration and the thickness of base. Those results could be explained theoretically by the electric field and the potential barrier in the emitter-to-base (EB) junction and the BC junction.
PSPICE simulation of transient characteristics of GaN based MSM structure UV detector grown by MBE
Xiangming Gao,
Shuo Wang,
Hongxia Ran,
et al.
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On the basis of optimizing the process conditions of molecular beam epitaxy (MBE), the GaN thin film with high quality was prepared by using sapphire (0001) vicinal substrate. HP-5000 type transistor characteristic tester was employed to measure the dark state current-voltage (I-V) characteristics of the GaN thin film metal–semiconductor–metal (MSM) structure grown on adjacent crystal surface by MBE. It was found that this kind of MSM structures had shown a rectifying contact characteristic. The dynamic photoconductive characteristics of the GaN based MSM structure and the transient photocurrent characteristics of the reverse bias diode were simulated by using PSPICE. The results showed that the transient photocurrent response time was in nanosecond level, under the condition of pulse width 800ps, wavelength 355nm light excitation.
Waveguide effect of Fe doped GaN alloy grown by MOCVD
Xiangming Gao,
Wenqi Zheng,
Tao Fan,
et al.
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The surface morphology and structural properties of Fe doped GaN alloy samples were analyzed by SPM9700 atomic force microscope and X LabXRD-6100 ray diffraction. The equivalent diameter of crystallite size was calculated to be 18nm according to the XRD data. The photoluminescence spectra of the samples were measured by 325nm continuous laser excitation at room temperature. The peaks position of the photoluminescence spectra of the samples was located at 450nm, 585nm and 665nm respectively. The waveguide effect was observed and analyzed. The peak wavelength of the waveguide is mainly in the 543nm. The results suggested significantly for further improvement of the performance of GaN based electronic devices and optoelectronic devices.
Facile solution processed MoO3 thin film as hole transportation layer for polymer solar cells
Chengxi Zhang,
Jiang Cheng,
Xiaoqing Liao,
et al.
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MoO3 hole transportation layer was prepared by a novel spray coating method under low temperature for polymer solar cell. The physical phase of spray coated MoO3 thin film was demonstrated by X-ray diffraction. The surface morphology of solution processed MoO3 (s-MoO3) and thermally evaporated MoO3 (e-MoO3) was characterized by metallurgical microscope and atomic force microscopy. The PSC device based on s-MoO3 HTL shows better photo to electron conversion efficiency (PCE = 2.93%) performance than PEDOT:PSS based devices (PCE = 2.80%), and the high Jsc obtained in s-MoO3 based PSC device indicates that the transportation across the s-MoO3 layer is unhindered. Finally, the stability of PSC devices based on different HTLs has also been investigated.
The ambipolar operation of lateral and vertical PbSe quantum dots field effect phototransistors
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We fabricate and investigate the photoelectrical characterization of PbSe QDs FEpTs Field Effect photo Transistors in lateral (LQFEpT) and vertical architectures (VQFEpT) respectively. Both LQFEpT and VQFEpT apply PbSe quantum dots as active layer, with different channel length of 0.1mm and 678nm respectively. The VQFEpT apply Au/Ag nanowires (NWs) as source transparent electrode connecting with Au source electrode. The ambipolar operation of both FEpTs show low power consumption, delivering high drain current at VSD = VG = ± 4 V. The VQFEpT exhibit higher photocurrent up to 4mA, three orders magnitude higher than that in LQFEpTs (16μA), owing to the superior carrier transportion in the shorter channel. As a result, higher photo responsivity (8×104A/W), specific detectivity (2×1012Jones) and gain (1.3× 105) are achieved in VQFEpT. The all-solution processing vertical architecture provide a convenient way for IR photo detectors with high performances.
Poster Session
Quality assessment for spectral imaging
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Recent research in the area of image quality assessment has been focusing almost exclusively on greyscale and color images. The advent of technologies such as remote sensing, biomedical and industrial imaging however demands this research to be extended to multi/hyper spectral images. Spectral imaging has more judging essentials than greyscale or color imaging and its image quality assessment task intends to cover up all-around evaluating factors. This paper presents an integrating spectral imaging quality assessment project, in which spectral-based, spatial-based and radiometric-based quality evaluation behavior for one remote-sensing hyperspectral imager are jointly executed. Spectral response function is worked out and spectral performance is further judged according to its FWHM and spectral excursion value. Spatial quality assessment is worked out by MTF computing with an improved slanted edge analysis method. Radiometric response ability of different spectral channels is judged by SNR computing based upon local RMS extraction and statistics method. Improved noise elimination and parameter optimization method are adopted to improve the evaluation fidelity. This work on spectral imaging quality assessment not only has significance in the development of on-ground and in-orbit spectral imaging technique but also takes on reference value for index demonstration and design optimization for spectral instrument development.
Technique of multilayer to improve holographic performance of photopolymer for high density data memory
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Recently growing interest has been focused on photopolymers for their advantages in holographic storage memory. For large memory capacity, one of the basic requirements is that the recording material thickness must be 500 μm or thicker. Nevertheless, the attenuation of the light in depth due to absorption limits the effective optical thickness inside material, which reduces the holographic performance of photopolymer. In this work, the influence of the effective optical thickness of photopolymer on its holographic characteristic was studied theoretically and experimentally. To overcome the attenuation of gratings for a better uniformity, a technique of multi-layer was introduced, by adjusting concentrations of dye along the depth of photopolymer to compensate the attenuation of recording light due to absorption. Multi-layer photopolymers based on PVA/AA with thicknesses more than 500 μm were designed, fabricated, and characterized experimentally, exhibiting better Bragg selectivity. The attenuation of gratings was suppressed, and the effective optical thickness was enhanced. More holograms were stored in multi-layer material by angular multiplexing, and the cumulative grating strength was enhanced, leading towards larger holographic storage capacity. Also, with the theoretical simulation on the distributions of the gratings inside the material, the improvement of multi-layer technique in holographic performance is shown.
Detection and extraction of mixed signals in hybrid optical fiber sensing system
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A new hybrid optical fiber sensing system is proposed, which uses optical filter and coherent detection method to separate the mixed Rayleigh, Brillouin and Raman signal. In the sensing system the optical Raman signal is filtered out by corresponding optical fiber grating, and then by an optical local oscillator the optical Rayleigh and Brillouin signals are converted to radio frequency (RF) signals through a balanced photodetector (BPD) with two phase-inverse output ports. Then the Rayleigh RF from one output port of the BPD is filtered out by a RF filter with center frequency of 200MHz and bandwidth of 5MHz, and then the power of the RF Rayleigh signals are extracted by a RF power detector. And for the RF Brillouin signal extraction, a band pass filter with center frequency of 11.45GHz and bandwidth of 1.7GHz is used to filter the RF signals from the other output port of the BPD, so that the RF Brillouin signals are purified and then by a mixer and a sweeping RF source the details of the RF Brillouin spectra are characterized. The method can make the hybrid optical fiber sensing system more compact, and enhance the sensing performance, which benefits for the cost reduction.
Third order optical nonlinearities of TiO2/PS composite system
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A TiO2/PS composite system is prepared by chemical vapor deposition which is a common technique in preparation of nano-materials. We report the measurements of the nonlinear refractive index of the TiO2/PS composite system as measured by the reflection Z-scan technique. The large magnitude of the third-order nonlinear coefficients of the TiO2/PS composite system shows that it is a promising candidate for further material development and possible photonic device applications.
Influence of annealing treatment on the dielectric properties of poly(vinylidene fluoride)
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Untreated and annealed PVDF films in same crystalline phase were fabricated via different processes, and the effects of annealing treatment on the dielectric properties of PVDF films were studied. It has been found that the annealing treatment eliminates the micro pores in the PVDF films. As a result, the annealing treatment shows to exert strong influence on the relative permittivity and leakage current of PVDF films. Compared with common untreated PVDF film, the annealed PVDF film presents a higher relative permittivity about 8.7 in a 1 kHz electric field and a lower leakage current around 3.04 μA under a 1000 kV/cm electric field. However, the annealing treatment has little effect on the dissipation factor.
Improved single image super-resolution based on edge directed interpolation
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Single image super-resolution is one of the most prevalent techniques in digital image processing with a wide range of applications. In this paper, we analyzed the well-known new edge directed interpolation (NEDI) and proposed an improved single image super-resolution method based on edge directed interpolation which could preserve the edge features and reduce common artifacts efficiently. In order to obtain a good tradeoff between quality and speed, a new scheme which moves local window along edge direction is applied. Simulation results demonstrate that the proposed algorithm improves the subjective quality of the interpolated images over the other conventional interpolations with competitive computation complexity.
Effect of the introduction of Ag on the microstructures and electrical properties of polycrystalline VO2 thin films
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We investigate the effect of the introduction of Ag on the microstructures and electrical properties of polycrystalline VO2 thin films prepared by reactively sputtering process. X-ray diffraction patterns and Raman spectra indicate that Ag/VO2 composite thin films have similar monoclinic structure to undoped VO2 films. However, the existence of Ag greatly reduces the grain size of monoclinic VO2. Differently, the data from scanning electron microscopy and atomic force microscopy reveal that the introduction of Ag obviously increases the particle size and root-mean-square(RMS) roughness of VO2 films. The opposite changing tendency between the particle size and grain size probably results from the existing forms of Ag in Ag/VO2 composite thin films. On one hand, the existence of Ag in VO2 lattice and in the grain boundaries inhibits the growth of monoclinic VO2 crystals, thus the grain size decreases. On the other hand, redundant Ag forms pure cubic Ag phase with much larger particle size due to the strong tendency of the Vomer-Webber growth of Ag at elevated temperature. Ag particles in VO2 films cause rougher surface morphologies and larger particle size than undoped VO2 films. The electrical properties Ag/VO2 composite thin films were also investigated. A small amount of Ag depresses the amplitude of semiconductor-metal phase transition (SMPT) of VO2. With the further increase of Ag concentration, the SMPT feature of VO2 thin film gradually disappear. This provides a promising approach for preparing thermal-sensitive vanadium oxide films with high temperature coefficient of resistivity and without SMPT feature for bolometer infrared detectors.
Optical properties of thermally evaporated ultra-thin Al, Ag and Cu films
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In this article, ultra-thin Al, Ag, Cu thin films with thickness d ~10nm are prepared by thermal evaporation, Ellipsometer
and Spectrophotometer are used to measure Ψ, ∆, R and T of samples. Based on the characteristics of different metal
materials, we choose proper physical model to analysis the dielectric function. Experimental results show that the
method of Ellipsometer with transmittance data fitting can describe optical constants of ultra-thin metal films, and all the
parameters of Ψ, ∆ and T show a good fitting result. Moreover, the reflection of samples simulated by MathCAD
software using Fresnel coefficient equations also follows the measured reflectance data.
Fabrication and parameters calculation of terahertz detector with resonance cavity structure
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Terahertz (THz) detector indicates great potentials in detecting application because of real-time, compact bulk and unique spectral characteristics. Small dimension and integration THz detectors based on resonance cavity structure were designed and simulated to get optimizing THz detector parameters from the simulation results of membrane temperature changing. The THz detector was fabricated with complex semiconductor process and three dimension thermal variation of resonance cavity were obtained by simulation to identify the resonance cavity design. The electrical response time of THz detector could be as low as 5ms, which is suitable for the application of fast response THz detecting.
Image metric analysis of laser jamming effect based on edge strength similarity and gray mean square error
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Laser jamming plays an important role in the countermeasure to optoelectronic imaging systems. The influence of laser jamming on optoelectronic imaging systems was introduced briefly. In order to evaluate the performance of laser jamming objectively, quantitatively and precisely, a comprehensive image metric combining the edge strength similarity(ESM) with gray mean square error(MSE) was proposed from the view of laser jamming images. The computation methods of edge strength similarity and gray mean square error were provided. The metric computed the edge strength similarity between target image and background image, and gray mean square error between target image and reference image comprehensively to evaluate the laser jamming performance quantitatively. Computing the edge strength similarity between target image and background image could be viewed as a local evaluation metric, and computing the ray mean square error between target image and reference image could be viewed as global evaluation metric. The two metric was combined to evaluate the performance of laser jamming comprehensively. Experimental results of laser jamming in and out the field of view showed that the proposed metric could realize quantitative appraisal of laser jamming performance on optoelectronic imaging systems.
Surface modification on GaAs by in-situ pulsed UV laser
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A single-beam of UV pulse laser (355nm/10ns) was used to irradiate the as-grown GaAs (100) surface in-situ in molecular beam epitaxy with pulse numbers from 1 to 6 at laser intensity of 52.5 mJ/cm2/pulse. It was observed that the irradiated GaAs surface morphology depended strongly on the pulse number. For single pulse irradiation, small nano-dots (NDs) with high density were produced on the surface. The size of NDs increased and nano-rings (NRs) were observed with the increasing of pulse numbers. The surface was completely dominated by NRs at 6 pulses of laser irradiating. Arsenic atoms were selectively desorbed away from GaAs surface by laser irradiation leaving plenty of naked Ga-atoms to form small metal-dots of Gallium. Ga-rich NDs transferred to Ga droplets with the increased number of the laser pulses. NRs formed just as the traditional droplet-epitaxy process when the droplet size grew up to a critical size. Nano-drill process played an important role in the process. This research was supposed to provide a novel and promising solution for more controllable nano-fabrication of various semiconductor materials of MBE growing, including but not limited to GaAs reported here.
Synthesis and structure property relationship of several dicyanomethylene malononitrile derivatives
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Based on the intramolecular charge-transfer (ICT) molecule 2-[bis-(4'-diethylamino-biphenyl-4-yl)-methylene]- malononitrile (D7), two novel malononitrile derivatives (C1 and C2) with 2,7- and 3,6-substituted fluorene as conjugated backbones, respectively, were synthesized, which had the same electro-donor and acceptor groups as D7. The effects of the conjugated backbone and substitution site on optical properties of these compounds were investigated. 3,6-substituted fluorene is a better conjugated unit for ICT compared to 2,7 substitution site, whereas it is still weaker than diphenylmethyl unit in D7. However, due to the rigidity of fluorene, C2 possesses much higher fluorescence quantum yield. The results are supported by TD-DFT calculation. This study develops theoretical basis for designing effective optical or electronic materials.
A room temperature terahertz photodetector based on In0.53Ga0.47As material
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A terahertz photodetector was designed based on the novel room-temperature photoconductivity theory we proposed before. Prototype detectors with different sizes of photo-active area was fabricated on In0.53Ga0.47As material. Detectors' I-V property were tested, and signal response to a 0.0375THz source were measured. Results indicated that our detectors performed outstanding responsivity and respond speed. The room-temperature responsivity was estimated to be on the order of 104 V/W, the corresponding noise equivalent power (NEP) was estimated to be on the order of 10-12 W/Hz1/2, and the response time constant was calculated to be 1.06×10-5 S. Finally, our room-temperature photoconductivity theory was confirmed to be detectors’ respond mechanism via experiment and estimation.
The study on the generation method of two-dimensional airy beams based on digital blazed grating
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The common generation methods of two-dimensional airy beams were introduced briefly. The disadvantage of generation method by utilizing traditional two-dimensional digital phase masks was analyzed as well. Based on this, the digital blazed grating was introduced, as well as its corresponding theories. It was proposed that the traditional two-dimensional digital phase mask and the alterable digital blazed grating could be combined to generate a comprehensive phase mask. Thus, the diffraction orders of the airy beams could be controlled by changing the periods of improved comprehensive phase masks. Compared to the traditional two-dimensional digital phase masks, the airy beams generated by the proposed comprehensive phase mask had the advantage of controllable distances between different diffraction orders. At the same time, the specific order of the Airy beams could be strengthened, and the others could be weakened, which was useful to the subsequent study on the propagation and control of two-dimensional airy beams. The experimental results showed that: the proposed comprehensive phase masks could distinguish between the different diffraction orders of generated Airy beams. As a result, the mutual interference between different diffraction orders could be avoided effectively.
DFB fiber laser hydrophone enhanced through polyurethane end surface pulling
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A fiber laser hydrophone enhancing sensitivity through polyurethane end surface pulling is presented. After the relation between acoustic pressure sensitivity, dynamic performance and polyurethane material of the hydrophone are respectively described by theoretical model and ANSYS simulation, the polyurethane used for enhancing whose parameters are optimized is prepared. Prototypes of the hydrophone are fabricated and tested in vibration liquid column and Qiandao Lake experimental field. The average acoustic pressure sensitivity is -142.70dB(0dB=1rad/μPa)with the fluctuation less than ±2dB in the frequency range of 10~2000Hz. The result shows that DFB fiber laser encapsulated by polyurethane end surface ensures the high sensitivity, its fluctuation used in underwater sound detection is restrained at the same time, which is of great significance to promote the engineering application of fiber laser hydrophone.
Performance of terahertz photodetectors based on MSM structures of Mercury-Cadmium-Telluride under low temperature
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High sensitive Terahertz detection can be achieved by properly constructing Metal-Semiconductor-Metal (MSM) structure with semiconductor materials. In this study, Mercury-Cadmium-Telluride (MCT) film was used to fabricate MSM Terahertz detectors. The working temperature was altered to study the IV characteristics of MCT detectors under RT and 77 K, as well as the response signals to 0.0375 THz and 150 GHz sources. The results showed that the response speed was greatly improved under low temperature condition, and the time constant decreased to smaller than 3 μs at 77 K, comparing to some hundred μs at room temperature (RT). However, due to the variation in IV characteristics under low temperature, the working current of the detector was much lower than that at RT for identical voltage bias, and the low frequency response was 6 times larger than that at RT under the same bias current. The MCT detector is shown to be highly sensitive for THz detection and its detection ability can be further improved by lowering down the working temperature.
Scratch detection in metal surface by blasting using Gabor filters
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Sand blasting process can produce fine random concave and convex surfaces on the surface of the workpiece, which make the collected image background of the workpiece complex and the defects difficult to detect. Especially for the detection of low-contrast scratches, scratch depth is less than the depth of sand blasting surface. Common edge detection methods and threshold segmentation methods are difficult to effectively extract the scratch defect. According to the vertical characteristics of scratches direction in the spatial domain and the spatial-frequency domain, a method based on Gabor filter is proposed for the detection of scratch defect. Firstly, 36 Gabor filters with different directions are used to extract the directional feature of the image. Then, using the gray threshold method to segment the scratch regions in 36 different directions and merge the scratch regions. Finally, the morphological processing is used to remove the noise interference and connect the scratch regions which are not continuous. The experimental results show that the method is feasible and robust. Compared with the hysteresis threshold algorithm, the algorithm extracts the edge of the scratch without burr and has high precision.
Magnetically tunable giant Goos-Hänchen shift of reflected terahertz beam
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We propose a scheme to manipulate the Goos-Hänchen shift of a terahertz wave reflected from the prism/magnetic dielectric. By adjusting the external applied magnetic field, the refractive index of the magnetic dielectric can be changed, so the Goos-Hänchen lateral shift is dynamically tuned. Numerical calculation results further indicate that the proposed configuration has the potential application for the integrated terahertz wave switch with the extinction ratio of 18.5dB at terahertz wave wireless communication frequency of 0.857THz.
Fabrication and infrared absorption of tellurium doped silicon via femtosecond laser irradiation
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Doping silicon with chalcogens (S, Se, Te) via femtosecond-laser irradiation lead to increase the absorptance of Si in both visible and infrared region, so chalcogens doped silicon have great potential for use in Si-based optoelectronic devices. Tellurium doped silicon was fabricated by femtosecond-laser irradiation of Si with Si/Te bilayer films. The influence of distance between the sample surface and the laser focus in the process of fabricating micro-structured Si was studied. The results show that the sample surface cannot be located in focal plane, nor is far from the focal plane, suitable distance is necessary to produce regular columnar structure. And the surface structure of doped silicon is vitally important to high absorptance. In addition, we report the dependence of surface morphology and optical properties on scanning speed. The absorptance increases over the entire wavelength as the scanning speed decreases.
The new high-speed switching study of ultra-short laser pulse technology
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Ultrafast phenomenon has presented widely in natural phenomenon and scientific and technological research. Therefore, study on ultrafast phenomenon is of great important in many research and technology fields. In recent years, the development and application of ultra-short laser pulse has been covered many areas. It has been developed into a powerful tool used to research ultrafast phenomena. In the implementation process of the ultra-short laser pulses, high-speed switching plays a vital role. The difficulty of high-speed switching design is to make the ultrafast electric pulse load on the both ends of the crystal with minimum distortion and delay. It is very difficult to switch electro-optic crystal at a high frequency in traditional method. In this paper, a new method is designed, which combined the electro-optic crystal and micro-strip line. The crystal is a part of the transmission path and the signal path of the micro-strip line is broadened or narrowed continuously to make the impedance matching to 50 ohm. The good match between pulse signal and the crystal make sure the high frequency switches of the crystal. The amplitude loss is less than 11%, and the delay is less than 1 nanosecond.
Realizing white organic light emitting device with direct hole injection structure by manipulating electron transport
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White organic light-emitting devices (WOLEDs) with a novel direct hole-injection structure based on the hole transport capability of bis[2-(4-tert-butylphenyl) benzothiazolato-N,C2'] iridium(acetylacetonate) [(t-bt)2I-r(acac)] were fabricated. By inserting an electron-blocking layer, we successfully manipulated electron transport and achieved white light emission. A maximum luminance of 26020 cd/m2, a maximum current efficiency of 22.37 cd/A and a maximum power efficiency of 18.99 lm/W were obtained. This novel structure can significantly simplify the production processes of WOLEDs and deserves further investigation.
Synthesis and characterization of lithium tantalate thin films fabricated by sol-gel method
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Multilayer lithium tantalate thin films have been successfully prepared on Pt/Ti/SiO2/Si(100) substrate using sol-gel and spin-coating method. Polycrystalline perovskite films were obtained through pyrolysis at 400°C and subsequent calcination at various temperatures from 500°C to 700°C for 1h, which were optimized by means of X-ray diffraction, Raman spectroscopy and thermal analysis. The morphology on the top surface and fractured cross section of LT films was observed by a field-emission scanning electron microscope. The 300 nm thick LT film annealed at 650°C exhibited a dielectric constant of 19.8 and a loss tangent of 0.06 at10KHz.
Effects of annealing time on the application of vanadium dioxide films in smart windows
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Vanadium dioxide (VO2) films have great potential applications in photoelectric switching, storage devices, terahertz modulators and smart windows, due to the abruptly insulator-metal phase transition (IMT) near room temperature. In this research, vanadium oxide films were deposited by DC reactive magnetron sputtering in different annealing time of 450°C on glass substrates. As for electrical properties, the increasing of annealing time turns out sheet resistance increases at first, and then decreases in insulating phase, vice versa in metallic phase. In optical properties, the visible transmittance of VO2 films initially drops with annealing time prolonging, afterwards the transmittance slightly recovers. Differences between the electrical and optical are due to the grain size. Moreover, VO2 film annealing 15 min presents excellent visible transmittance, highly near-IR modulation efficiency (about 92% at a wavelength of 1100nm) and the lowest phase transition temperature (55.7°C). This result indicates that an appropriate annealing ambient can facilitate the application of VO2 film in smart windows.
Simulation and analysis of image sensor's TEC cooling package based on ANSYS Icepak
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In the use of image sensors such as CCD, CMOS and so on, the noise caused by thermal dark signal will influence the imaging results to a certain extent. Dark current noise exists in every photoelectric devices and it is directly related to the temperature. So it’s a principle way that cool the image sensors’ temperature to suppress the dark current noise. This article presents a kind of TEC cooling package integrated with four stages TEC, a heat sink and an insulating cavity, to meet the requirement of image sensors’ refrigeration. Theoretical analysis of this cooling package was done from the view of heat transfer. The modeling and thermal simulated analysis are performed by finite element simulation analysis software ANSYS Icepak, comparing the experimental results in the conditions of different ambient temperature, different heat load and vacuumizing or filling the cavity.
A bidirectional image matching algorithm based on SIFT features
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Matching accuracy plays a vital role in image matching and image recognition. In order to improve the accuracy and robust of image matching, a bidirectional matching algorithm is proposed to delete false matching relationships, so the matching accuracy can be improved. Based on the unique constraint of unilateral matching, the positive matching results from template image to the image to be matched can be obtained. Then the negative matching results from the original image to be matched to the original template image can also be obtained. Now the final bidirectional matching results can be achieved by the intersection of the positive and negative results. Precision ratio is taken as the evaluation indicator. Through various image transformation scenes, experimental results show that the proposed algorithm has a higher precision ratio on the contrast of unilateral matching algorithm. So the proposed bidirectional matching algorithm can improve the precision ratio and robust of unilateral matching algorithm and improve the matching accuracy of image matching.
The method of color restoration based on CYMG complementary colors CFA pattern
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Color filter arrays(CFA) based on complementary colors(CYMG) has been designed and used with the main advantage: higher spectral sensitivity and wider bandwidth than RGB CFA, especially in the low-light or short integration time environment. As for the interline-transfer, interlaced-readout complementary colors CFA pattern CCD, we propose a method of color restoration by the conversion of CYMG-YUV-RGB color space. Specifically, summing horizontally adjacent pixels from raw data can provide estimates of the luminance channel Y, while subtracting horizontally interlaced adjacent pixels can provide estimates of chrominance (color difference) channel U and V individually. A 2 × 2 pixels block of raw data is the smallest cell to figure out Y, U, V channels. Subsequently, transform YUV to RGB linearly according to the conversion formula between CYMG and RGB. At last, the raw data from CCD can be restored to RGB signals which is convenient for post-process, such as white balance. Additionally, we adopt an improved median filter to U and V channels to remove the edge zipper noise caused by interpolation, which can optimize the image quality.
An automatic white balance method based on gray world and coincidence of chromaticity histogram
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Digital image camera has received more and more attention because of its convenience in storing and transferring, the still exist problems about it are also hot topics of research. Auto white balance is one of the problems, it’s the result of differences between image sensors and human eyes. If the illumination of environment has changed, color cast will happen in image from sensors, but image from eyes due to color constancy won’t. For weakening this inconsistence and acquiring image of same scene under canonical illumination, color adjustment according to color temperature of environment should be considered. In this paper, an auto white balance approach combined gray world and coincidence of chromaticity histogram (GWCCH) is proposed. It’s based on basic assumptions of these two methods, measures color components in image, and selects appropriate routine and arguments to implement auto white balance. In the experiment results, the proposed method can meet the theory of gray world (GW) or coincidence of chromaticity histogram (CCH) respectively, and get good effect in more scenes than these two methods.
Light field microscope with square aperture and the reconstruction algorithm
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Light field microscope (LFM) can be built by inserting microlens array into a traditional microscope. Different perspective image of the sample could be obtained by reconstruction algorithm dealing with the four dimensional light field information captured by the detector. Since light field microscope has been always studied in laboratory, the reconstructed image quality which depends on the microlens array is still not too high. The pixels between every two sub image of microlens array is waste when circle aperture of objective is used. In this article, rectangular aperture has been used in this paper to improve the utilization of the CCD, which is favorable to reconstruction algorithm. Progress has been made in reconstruction algorithm which can improve the reconstruction image quality, wave optic theory has been used to calculate the PSF of the whole imaging system due to the short object distance, subpixel interpolation algorithm has been combined with the reconstruction algorithm of LFM to improve the image quality, good imaging quality has been obtained through the improved algorithm.
Measurement of scattering laser energy density distribution in optical extinctive chambers based on CCD imaging method
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The CCD imaging method is usually used in the far-field laser energy density distribution measurement, and the method is simple, reliable. The scattering laser energy density distribution in optical extinctive chambers is one of the most important factors affecting the performance of hardware-in-the-loop simulation system for laser guided weapon because of the weak signal, therefore, how to accurately measure the scattering laser energy density distribution is the key factor to the performance of the laser guided weapon evaluation. In this paper, the method of CCD imaging for scattering laser energy density distribution measurement in optical extinctive chambers was shown. Firstly, the principles and setup of measurement based on CCD imaging method were studied, and the model of scattering laser energy density measurement was simplified under special conditions. And then, the calibration process between the region division and the FOV (field of view) of CCD was described simply, the relationship between the gray value and laser energy density was found. Finally, the scattering laser energy density distribution in optical extinctive chambers was deduced by the measurement of the CCD’s gray value, and measurement errors were also analyzed.
Thermal strain and stress distribution of ZnTe/Si(211) and CdTe/Si(211) heterostructures
Yuan-zhang Wang
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The model of mismatch strain and stress distribution considering the premise of the material anisotropy was made in this article. The strain and stress distribution and the radius of curvature of ZnTe/ Si (211) and CdTe/Si (211) heterostructures were calculated. The results showed that the strain and stress profiles and curvature radius of ZnTe/Si(211) and CdTe/Si(211) are asymmetric along in-plane direction [1-1-1] and [01-1]. The strains of epilayer and substrate are both negative at room temperature 293.15K. The stresses in ZnTe and CdTe epilayers are both tensile while in Si substrates are compressive on the side of interface and tensile on the other side. Compared with the ZnTe/Si (211) heterostructure, CdTe/Si (211) showed low stress and large curvature radius.
An efficient algorithm based on the fast fuzzy theory for image and video dehazing
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Influenced by the climatic conditions, such as haze, there exist problems of weak visibility and low contrast for the images and videos captured outdoors. Recently, an effective image haze removal method based on dark channel prior has been proposed. However, the brightness of the result is usually not as bright as the atmospheric light, that makes the whole image looks dim. Besides, the execution speed of this method is slow. As a result, it cannot be applied to the situations with high real-time requirements, such as video streams. In order to solve these problems, an efficient algorithm for image and video dehazing is proposed in this paper. Firstly, the transmission map of hazy image based on the fast fuzzy theory is calculated. Then, according to the statistical principle of dark channel prior and the atmospheric scattering model, the haze-free image under ideal illumination can be restored successfully. Large number of experimental results have shown that, the proposed algorithm can obtain better haze-free results for single image compared with the previous method. More importantly, the execution efficiency has been improved greatly. As a result, video steaming can also be dehazed in real-time so as to meet the occasions with much requirements of industry.
Effect of doping copper-phthalocyanine and annealing treatment on the performance of polymer solar cells
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We have fabricated poly(3-hexylthiophene) (P3HT)/copper phthalocyanine (CuPc)/fullerene (PC71BM) ternary blend films. This photoactive layer is sandwiched between an indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT/PSS) photoanode and a bathophenanthroline (Bphen)/Ag photocathode. The thin films have been characterized by atomic force microscope (AFM) and ultraviolet/visible spectroscopy in order to study the influence of CuPc doping on the morphological and optical properties of the photoactive layer. We have also compared the J-V characteristics of two different organic solar cells (OSCs): ITO/PEDOT:PSS/P3HT0.5:PC71BM0.5/Bphen/Ag and ITO/PEDOT:PSS/P3HT0.3:CuPc0.3:PC71BM0.4/Bphen/Ag with and without annealing. Both structures show good photovoltaic behavior. Actually, the incorporation of CuPc into P3HT:PC71BM thin film improves all the photovoltaic characteristics. We have also seen that thermal annealing significantly improves the optical absorption ability and stabilizes the OSCs making it more robust to chemical degradation.
The effect of interlayer on the performance of double emitting layer OLEDs
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Double emitting layer (yellow and blue) phosphorescent organic light emitting devices (OLEDs) were fabricated using different materials as the interlayer. The structure of the devices is ITO/NPB/(t-bt)2Ir(acac)/interlayer/BCP: FIr6/Bphen/Mg:Ag. Interlayers are mCP, TPBi, and TAPC, respectively. Comparing three kinds of interlayer, the luminescence characteristics of the devices are investigated. The results show that the current efficiency and the brightness are greatly improved because of the application of interlayer. Using the mCP as the interlayer, we obtained the maximum current efficiency of 39 cd/A and the maximum brightness of 18360 cd/m2, the color stability is also be enhanced.
Theoretical investigation of a novel logic device based on plasmon-induced transparency
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A novel and compact metal-insulator-metal (MIM) waveguide coupled with dual hexagonal ring resonators is proposed and theoretically investigated using the temporal coupled-mode theory and finite-difference time-domain (FDTD) method. The numerical simulation results indicate that when the resonance wavelengths of the two hexagonal ring resonators differ from each other, the plasmon-induced transparency (PIT) phenomenon can be obtained. Furthermore, this plasmonic device is also demonstrated can be used as a logic device which implements the function of fundamental logical operations XOR and XNOR. This device is of significance to optical computing and optical networks-on-chip, and it may help to open up a new field for the application of surface plasmon polaritons (SPPs).
A general crosstalk noise analysis model for the N-port nonblocking optical router in ONoC using WDM
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The optical network-on-chip (ONoC) using WDM is the most promising candidate in MPSoCs for their strengths of high communication bandwidth, high energy efficiency, high transmission speed, lower latency and power dissipation. However, when WDM is utilized, new crosstalk noises are introduced, especially the four-wave mixing (FWM) crosstalk noise. In this paper, we propose a general crosstalk noise analysis model for the N-port nonblocking optical router in ONoC using WDM. As a case study, the transmission loss, crosstalk noise, and optical signal-to-noise ratio (OSNR) of the five-, six-port routers with eight wavelengths are presented. The results show the average OSNR is different for the different wavelength signals transmitted in the both routers. For the same channel, the OSNR is different among the signals with different wavelengths. For the same wavelength signal, the OSNR of different channels is also distinct.
An optofluidic variable optical attenuator based on magnetohydrodynamic drive
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With the development of optical communication, the optical attenuator becomes an important passive device. It is widely used in power equalization of DWDM system and photo detectors. Here an optofluidic variable optical attenuator (VOA) based on magnetohydrodynamic drive is presented. This chip uses microfluid and compressible air to adjust optical attenuation, where the fluid-drive technology uses magnetohydrodynamic (MHD) drive. The driving pump consists of two electrodes and a permanent magnet (NdFeB) that under the microfluidic channel. Only several volts voltage is needed in operation. There are no movable mechanical parts in this variable optical attenuator, so its volume is small. This variable optical attenuator has a simple structure and a low voltage advantages, and it is easy to control and integrate. The proposed VOA gives a new method for looking for small, low voltage and adjustable VOAs.
A research on high-speed and large-capacity interface technology basing on fiber channel
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To meet the demand of complicated ATP system to control in real time and smoothly, this paper selects fiber channel as the data transmission mode. It designs a star-shaped electrical platform which can combine data acquisition, processing, transmission, and exchange in one. Also by using Rocket I/O GTX transceiver embedded in Xilinx Virtex-6 FPGA as the physical layer, it implements real-time data transmission and exchange basing on 24 fiber channels to support up to 128 custom serial protocols. The main points of electrical platform design are presented in this paper. Furthermore, the method of FPGA implementation and major configuration parameters of Rocket I/O GTX transceiver are discussed in detail. Also the experimental results of hardware debugging in ISE environment show that the 24 fiber channel transmission is stable and right when the system reference clock is 250MHz, single-channel line rate is 2.5Gb/s. The use of fiber channel has improved data transmission efficiency and reliability between the units of ATP system. Also hardware debugging workload is significantly reduced by universal configurable software design.
Porous silicon biosensor for Echinococcosis detection based on fluorescence spectroscopy
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Agriculture and animal husbandry area, such as Xinjiang, has high rates of hydatid disease. Protein P38 of Echinococcus granulosus has practical value in diagnosis of hydatid disease, and it may be used as a diagnostic marker and a prognostic index. In recent years, the development of biosensors based on porous silicon has been developed rapidly. In this experiment, the protein P38 detection based on fluorescence changes of porous silicon following protein P38 molecule adsorption. The results of the tests indicated that, with the increase of antigen concentration, the fluorescence decrease of porous silicon is also increasing. It is provided the foundation for the basic research of the molecular mechanism of P38, and diagnosis and treatment of cystic echinococcosis.
A biosensor platform based on Raman spectroscopy of porous silicon
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Porous silicon suitable for optical detection as a biosensor platform is fabricated. The morphology, structure and Raman properties of porous silicon have been studied and protein P38 of Echinococcus granulosus was determined by the porous silicon Raman intensity changes following protein P38 of Echinococcus granulosus molecule adsportion. The results of the tests indicated that, when antigen is added into the porous silicon, the Fourier transform Raman intensity decrease of porous silicon is also increasing.
Detection of terahertz radiation using improved uncooled focal plane array detector
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A terahertz (THz) microbolometer detector and corresponding real-time imaging system were introduced in this paper. A 10nm NiCr thin film was integrated in the micro-bridge structure as the THz absorption layer by magnetron sputtering and reactive ion etching (RIE), and its improvement of THz absorption was verified by optical characteristics test. Through complicated semiconductor process, a microbolometer detector of 320×240 THz focal plane array (FPA) was prepared. And a real-time imaging system was established to identify the perfomance of this detector. The results demonstrated that the detector could get conscious THz image using a 2.52 THz far-infrared gas laser as THz radiation source.
Design and analysis of polarization splitter based on dual-core photonic crystal fiber
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We propose a novel structure of polarization splitter based on symmetric dual-core PCF with triangular lattice. The polarization-dependent coupling properties for x and y polarization modes, including coupling length, coupling length ratio (CLR) and propagation process in the designed splitter, are numerically investigated by using the full-vector finite element method (FEM) and the semi-vector beam propagation method (BPM). The simulation results show that CLR can be tuned to be about 4/3 and 3/2 at λ = 1.55 μm to meet the requirement of polarization split by optimizing the geometric parameters. For the case of CLR = 4/3, the polarization splitter with a total physical length of 3.12 mm is obtained and its extinction ratio is as low as -48 dB at λ = 1.55 μm.
A novel method to real-time offset correction for frame transfer CCD
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The traditional CCD offset correction processing method is to obtain normal exposure image and dark field image respectively. In the later image processing, use normal exposure image minus the dark field image. Although traditional method can offset correction, but cannot to realize real-time offset correction. Because the traditional method is to obtain offset correction after acquire normal exposure image and dark field image, while the normal exposure image and dark field image is not acquired at the same time. This method would reduce the offset correction precision. A novel method to real-time offset correction for frame transfer CCD is proposed in this paper. The method is based on the improvement of the traditional frame transfer CCD driving timing and CCD signal processing sequence. The traditional frame transfer CCD driving timing is exposure, frame transfer and read CCD level shift register. An offset correction line is added before read CCD data storage area to acquire the offset variation of the each frame image. Take it as a normal image data. In CCD signal processing algorithm to offset calculation and correction. This novel method can correct the offset of each frame image each pixel data real time. In this way the effect on the images from the variation of the offset caused by factors such as the working temperature and the aging of electronic devices in CCD signal processing circuit of CCD camera is restrained.
Controllable preparation and optical properties of Ag columnar thin films
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Noble metal nano-structured thin films show great electromagnetic enhancement due to the surface plasmon resonance effect. It can be used for surface enhanced Raman scattering (SERS), which means markers of ultra low concentration can be detected, having great potential in biosensing applications. In this work, we introduce glancing angle deposition (GLAD), which is based on the traditional physical vapor deposition, to prepare vertical columnar thin films (CTFs). Anodic aluminum oxide (AAO) is used as template during vacuum deposition, and nanodots of ordered distribution are obtained. Subsequently, these nanodots are used as the pre-constructs in GLAD, and the fabricated columns have a much bigger separation. Rhodamine 6G (R6G) SERS spectra of the nanostructure thin films are measured to study their optical properties. Due to the separation of columns, CTFs on nanodots show stronger intensity than CTFs on blank substrates. What’s more, the uniformity is also improved by the separation, making the substrates more applicable for biosensing. CTFs on nanodots of different heights are prepared. SERS measurements show that as the height increases, SERS effect increases due to much more hot spots of electromagnetic enhancement and coupling. Our method proves to be a feasible, low-cost, large-area preparation method for ultra high sensitivity SERS substrate.
Research on method for improving depth of focus with Gaussian beam by super-resolving pupil filters
Xiaofeng Zhao,
Changqing Liu,
Hongcai Li,
et al.
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The general super-resolving theories for Gaussian beam have been investigated. The three-zone amplitude pupils and phase-only pupils are adopted to provide specific numerical descriptions of improvement of DOF, respectively. Simulated results of comparison between Gaussian beam and Uniform amplitude beam have been presented. Furthermore, some useful advices for the design of super-resolving pupils to increase DOF of the optical system based on Gaussian beam are given.
Ti-doped hematite photoanode prepared by spray pyrolysis method with enhanced photoelectrochemical performance
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Ti-doping hematite photoanode was investigated by easily spray pyrolysis method using self-made spray coating system. Doping with titanium can improve the photoelectrochemical performance of the pure α-Fe2O3 thin films. The key point is the effect of Ti doping on improving the conductivity and enhancing charge transfer. When doped with Ti element, Vfb of hematite film shifts negtively about 50 mV, which is good for the hydrogen evolution in the water splitting process. The best IPCE of Ti-doped hematite photoanode reaches 30% under 0.3 V bias at 400nm, ultimately.
Large area vertical Ag columnar thin films as highly sensitive SERS substrates
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Noble metal nanostructured thin films are of great interest as competitive surface enhanced Raman scattering (SERS) substrates due to their remarkable plasmonic properties in the visible wavelength. In this work, large-area vertical Ag columnar thin films of different thickness have been prepared on the glass substrates by the simple, cost-effective glancing angle deposition technique. The Raman spectra of R6G from these substrates are measured and the experimental SERS enhancement factor is found to have the maximal value of 2.5E+8 at the optimized thickness of 680 nm. Finite difference time domain simulations have been utilized to study the near-field plasmonic properties upon these films and the simulated structure is a geometric copy obtained from the SEM image topology rather than simplified regular nanostructures. The areal electric field enhancement is sensitive to the gap size and areal column density. The wavelength and polarization dependence of localized electric enhancement in subwavelength gaps, "hot spots", are studied and the electric enhancement at different film depths is also analyzed. The simulation SERS enhancement factors are calculated and show good agreement with the experimental ones. When the thickness increases, the areal electric field enhancement decreases while the number of adsorded molecules increases, so there exists an optimized thickness to maximize the SERS performance. These results help to further our understanding of the plasmonic properties of noble metal nanostructured thin films.
Low-voltage organic thin film transistors with solution processed hafnium oxide and polymer dielectrics
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Low-voltage pentacene-based organic thin film transistors (OTFTs) are fabricated with solution-process hafnium oxide (HfO2) as gate dielectric layer. The dielectric high-k HfO2 film was deposited from the sol-gel solution prepared by dissolving HfCl4(98%, Sigma-Aldrich) in ethanol at a proper concentration. We have investigated the effects of the insulating layer on device. As a result, the device with only HfO2 gate dielectric exhibited a good performance with a threshold voltage of -0.88 V, a sub-threshold swing of 1.12 V/dec, and a high field-effect mobility of 1×10-3 cm2/Vs. After employing a very thin PMMA film onto HfO2, the performance of the devices with bilayer dielectrics shows a great improvement. The mobility of these OTFTs can be further boost up to 1.2×10-2 cm2/Vs, and the sub-threshold swing reduced to 0.77 V/dec and the drain current on/off ratio increased almost 7 times. The PMMA insulator buffer layer can also effectively reduce gate leakage current. The results demonstrate that an appropriate polymer buffer layer is a favorable way to improve the performance of the OTFTs with good electrical stability.
64-element fiber laser sensing system with interferometric interrogation
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We have developed a 64-element fiber laser sensing system based on 8 wavelength and 8 space division multiplexing. The array consists of four 980nm pump source which illuminate eight group distributed feedback fiber lasers(DFB FL) and eight optical switches which addressing in turns. The wavelength shifts of the DFB FL are converted to phase changes by routing the reflected signal through a nearly path balanced fiber Michelson Interferometer(MI). Through introducing an improved symmetric phase recovering method based on a 3×3 coupler, the influence of light intensity and splitting ratio is decreased. A 64 channels real-time synchronous demodulation system has been realized based on FPGA.