Journals >Semiconductor Optoelectronics
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2020
Volume: 41 Issue 2
31 Article(s)
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Research Progresses of Radiation Damage Experiments in Laser Diodes
WANG Zujun, NING Hao, XUE Yuanyuan, XU Rui, JIAO Qianli, LIU Minbo, YAO Zhibin, MA Wuying, SHENG Jiangkun, and DONG Guantao
Laser diodes (LDs) applied in the space or nuclear radiation environments will be susceptible to the radiation damage, which induces the degradation of the LD performances. In this paper, the radiation experiment progresses of the LDs manufactured at different periods such as the GaAs LDs at forpart, the quantum well LLaser diodes (LDs) applied in the space or nuclear radiation environments will be susceptible to the radiation damage, which induces the degradation of the LD performances. In this paper, the radiation experiment progresses of the LDs manufactured at different periods such as the GaAs LDs at forpart, the quantum well LDs, and the quantum dot LDs are reviewed. The degradations of the LD radiation parameters induced by different particles or rays such as protons, neutrons, electrons, and gamma rays are briefly introduced. The key problems needing to be further resolved in the future are analyzed. This paper will provide the basis of the theories and experimental techniques for the investigations of radiation experiment methods, degradation, damage mechanisms, and adiation hardening of the LDs..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 151 (2020)
Study on 1550nm Semiconductor Lasers Used in OTDR
LIAO Ke, WANG Haoxuan, XIONG Wentao, CHEN Jian, ZHOU Yong, and TIAN Kun
The optical time domain reflectometer (OTDR) is a special instrument in the test of optical fiber communication link. As the key compoment of OTDR, the performance of semiconductor laser directly influences the characteristics of OTDR, such as test distance, test precision, etc. In order to meet the application requireThe optical time domain reflectometer (OTDR) is a special instrument in the test of optical fiber communication link. As the key compoment of OTDR, the performance of semiconductor laser directly influences the characteristics of OTDR, such as test distance, test precision, etc. In order to meet the application requirements of OTDR, a kind of ridged waveguide laser chip with separate confinement heterostructure (SCH)was proposed. The SCH can improve the output power and slope efficiency of the lasers. Meanwhile, the quantum well structure was adopted to improve the temperature characteristic. For the developed semiconductor lasers working at the wavelength of 1550nm±20nm, the output efficiency of the single mode fiber exceeds 60mW at the working current of 300mA under 25℃, and the rise/fall time is less than 1ns, meeting the requirements of long-distence and high precision in OTDR applications..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 159 (2020)
Self-powered Near-infrared Photodetector Based on Single-walled Carbon Nanotube/Graphene/GaAs Double Heterojunctions
TAO Zejun, HUO Tingting, YIN Huan, and SU Yanjie
In this paper, a self-powered near-infrared photodetector was fabricated based on a single-walled CNT (SWCNT) /graphene/GaAs double heterojunction structure. Due to the excellent photoelectric properties of GaAs and high carrier mobility of graphene, the photodetector exhibits a high photoresponsivity, detectivity and In this paper, a self-powered near-infrared photodetector was fabricated based on a single-walled CNT (SWCNT) /graphene/GaAs double heterojunction structure. Due to the excellent photoelectric properties of GaAs and high carrier mobility of graphene, the photodetector exhibits a high photoresponsivity, detectivity and the on/off ratio of 393.8mA/W, 6.48×1011Jones and 103, respectively. More importantly, combing the near-infrared light absorption of SWCNTs with the photo-generated carriers effectively separated by the SWCNT/graphene heterojunction, the spectral response of the double heterojunction device is broadened to 1064nm, breaking through the absorption limit of GaAs itself..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 164 (2020)
Relationship between Voltage of Lateral Anti-blooming Gate and Full Well Capacity in TDI Image Sensor
QU Yang, WANG Xinyang, ZHOU Quan, and CHANG Yuchun
Due to its excellent detection ability under low light illumination, time delay integration CMOS image sensor (TDI-CIS) can be applied in aviation detection and satellite remote sensing. However, it is easy to appear blooming phenomenon to affect observation when TDI-CIS is under higher intensity illumination. In this Due to its excellent detection ability under low light illumination, time delay integration CMOS image sensor (TDI-CIS) can be applied in aviation detection and satellite remote sensing. However, it is easy to appear blooming phenomenon to affect observation when TDI-CIS is under higher intensity illumination. In this paper, the mechanism of blooming is introduced firstly and a TDI-CIS with rectangle lateral anti-blooming gate which is arranged in vertical direction based on two different anti-blooming structures is designed. Imaging tests indicate that the voltage of anti-blooming gate (VABG) is negatively corrected with anti-blooming and full well capacity (FWC). Finally, the optimal VABG of 2.1V is obtained..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 169 (2020)
Design and Experiment of Three-dimensional Gradient Fiber Optic Vector Hydrophone
ZHANG Tao, HU Binjie, CHEN Chaoyu, GUO Yundong, DENG Zhiru, SHI Tao, and XU Dong
The basic principles of the gradient fiber optic vector hydrophone are elaborated, and the effects of component sensitivity and distance impact on the acoustic pressure sensitivity are analyzed. The structure design of the 3D gradient fiber vector hydrophone is completed. Samples of two-dimensional gradient fiber opticThe basic principles of the gradient fiber optic vector hydrophone are elaborated, and the effects of component sensitivity and distance impact on the acoustic pressure sensitivity are analyzed. The structure design of the 3D gradient fiber vector hydrophone is completed. Samples of two-dimensional gradient fiber optic vector hydrophones were manufactured and technically tested. Test results indicate, in the frequency range of 20~1000Hz, the acoustic pressure sensitivity of the gradient fiber vector hydrophone is basically consistent with the theoretical value, and its presents good directivity at 500Hz..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 173 (2020)
Design and Fabrication of Structure-decoupled Quadruple Mass MEMS Gyroscope
LI Minyang, ZHANG Weiping, GU Liutao, LIU Zhaoyang, and TIAN Mengya
A new structure design and preparation method of structure-decoupled quadruple mass gyroscope are proposed. Design of comb electrode and push-pull method are used to eliminate the second harmonic component of the electrostatic driving force, and the structure of folding beam is simulated, analyzed and optimized to effeA new structure design and preparation method of structure-decoupled quadruple mass gyroscope are proposed. Design of comb electrode and push-pull method are used to eliminate the second harmonic component of the electrostatic driving force, and the structure of folding beam is simulated, analyzed and optimized to effectively realize the structural decoupling of drive mode and sense mode. According to the structure of the gyroscope, a feasible process plan was designed and the practical processing was carried out. Samples of the quadruple mass gyroscope were finally made by using SOI and anode bonding process. Simulation results show that the resonant frequency difference between drive mode and sense mode is 7Hz, which means the structure is highly symmetrical. Through the harmonic analysis, the maximum displacement of gyroscope is 1290nm, the maximum displacement difference of driving frame is 60.75nm, and the maximum displacement of detection frame is 305.24nm, which means that the ideal decoupling effect is obtained..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 177 (2020)
Simulation and Design of Low Voltage Driven F-P Cavity Tunable Filter
REN Haojie, HOU Haigang, ZHU Lihui, and HUANG Qingwei
In order to select the optimal bridge deck structure, the voltage-displacement, stress and mirror flatness of four new folded beam bridge deck structures of Fabry-Perot(F-P) cavity tunable filters (with no holes, circular holes, square holes and diamond holes) were simulated using the multi-physics finite element COMSOIn order to select the optimal bridge deck structure, the voltage-displacement, stress and mirror flatness of four new folded beam bridge deck structures of Fabry-Perot(F-P) cavity tunable filters (with no holes, circular holes, square holes and diamond holes) were simulated using the multi-physics finite element COMSOL software. The results show that the displacement of the bridge deck with diamond holes is the largest under the same driving voltage. Meanwhile, the required driving voltage of the bridge with diamond holes is the smallest under the same displacement. The stress and flatness of the bridge with diamond holes can also meet the design requirements of filters. Then the filtering performance of the optimized folded beam bridge deck structure with diamond holes was analyzed by the Essential Macleod software. The results show that its filtering is excellent in the optical spectrum of 3~5μm tuning range, and can meet the requirements of low driving voltage and wide tuning range..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 182 (2020)
Study on Factors Influencing the Finesse of Resonator Fiber Optic Gyro
GUO Lijun, WANG Tianrui, HE Jiajie, and PAN Chenhao
The influence of polarization fluctuation noise and backscattering noise on the fineness of the resonant fiber optic gyro was analyzed. And an optical fiber ring resonance ring test system was set up. The experimental results show that, by using a polarization controller and a polarization maintaining light source to sThe influence of polarization fluctuation noise and backscattering noise on the fineness of the resonant fiber optic gyro was analyzed. And an optical fiber ring resonance ring test system was set up. The experimental results show that, by using a polarization controller and a polarization maintaining light source to suppress polarization fluctuation noise, the fineness and the resonance depth of the characteristic parameters of the fiber resonance ring can be increased from 64.67 to 101, and from 0.5033 to 0.712, respectively. And the ratio of the backscattered light to the main signal intensity in the fiber resonator was measured to be 0.0267%. The research results can provide a theoretical reference for the miniaturization and high sensitivity of the resonant fiber optic gyroscope in the future..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 187 (2020)
Optical Fiber Mach-Zehnder Refractive Index Sensor Based on Spindle Air Cavity
DAI Yang, WANG Tingting, SUN Jiacheng, WANG Fei, and HUA Wendong
A sandwich-structured all-fiber Mach-Zehnder refractive index sensor based on a spindle-type air cavity was designed. The spindle-type air cavity was manufactured by splicing and taper acommon single-mode optical fiber and a photonic crystal fiber. The spindle-type air cavity and cladding in the taper area serve as theA sandwich-structured all-fiber Mach-Zehnder refractive index sensor based on a spindle-type air cavity was designed. The spindle-type air cavity was manufactured by splicing and taper acommon single-mode optical fiber and a photonic crystal fiber. The spindle-type air cavity and cladding in the taper area serve as the referring and sensing arms respectively, then the Mach-Zehnder interference is established. The interference fringes of the sensor and the electric field distribution in the taper area were simulated respectively based on FDTD Solutions and COMSOL. The relationship between the trough wavelength of the index sensor and the environmental refractive index, the effective refractive index and the environment refractive index are obtained by simulations. The sensitivity is 1377.6 and 1436nm/RIU when the refractive index is 1.36~1.37 and 1.37~1.38 respectively.The extremely short interference arm is used to reduce the loss and the sensor has higher refractive index sensitivity..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 191 (2020)
Research on Special Modal Vibration Characteristics of Piezoelectric Resonators
LIANG Tianchen, WU Xiaosheng, and LI Zhichao
A miniaturized and low-cost vector analysis system is proposed to analyze the vibration characteristics of piezoelectric resonators. The system uses STM32 to control 4 DDS chips to generate the driving signals and the vector analytical orthogonal signals. By writing frequency control words to the DDS module, the signalA miniaturized and low-cost vector analysis system is proposed to analyze the vibration characteristics of piezoelectric resonators. The system uses STM32 to control 4 DDS chips to generate the driving signals and the vector analytical orthogonal signals. By writing frequency control words to the DDS module, the signals with sweeping frequencies are generated to excite the piezoelectric resonator. Vector analytical technology is used to obtain the amplitude and phase of the output at each sweeping frequency. The resonance frequency, quality factor (Q value) and phase parameters under the two special vibration modes of the piezoelectric resonator are extracted. The influence of driving signals on vibration characteristics of piezoelectric resonator are analyzed systematically..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 195 (2020)
A PGA Circuit on Digital Double Sampling ADC of CMOS Image Sensor
WU Zhijun, LI Yiqiang, PENG Song, and LI Mengtao
A PGA circuit on digital double sampling ADC of CMOS image sensor is proposed. The offset voltage introduced by mis-matching of amplifier and capacitance of PGA is collected by increasing the offset sampling capacitance CC. The relative double sampling and amplification is performed in the reset sampling and PGA amplifA PGA circuit on digital double sampling ADC of CMOS image sensor is proposed. The offset voltage introduced by mis-matching of amplifier and capacitance of PGA is collected by increasing the offset sampling capacitance CC. The relative double sampling and amplification is performed in the reset sampling and PGA amplification stage, the digital double sampling ADC will quantify the two-stage storage voltage and make the difference in the digital domain, so the fixed mode noise introduced by the circuit of PGA is eliminated. Simulations were performed on 0.18μm special process of CMOS image sensor. The results show that, the output offset voltage of PGA can be reduced to less than 1mV in the range of input offset voltage of -30~30mV, which greatly reduces the column FPN compared with traditional PGA with single linear relationship between output offset voltage and input offset voltage..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 200 (2020)
Surface Plasmon Resonance Fiber Refractive Index Sensor Based on MSM Structure
GUO Zhiyong, GE Yixian, SHEN Lingwen, ZHANG Peng, and GU Qinshun
Based on the surface plasmon resonance (SPR) effect, a fiber-optic refractive index sensor based on a multimode-singlemode-multimode (MSM) structure was designed. The structure of the MSM is constructed by optical fiber fusion, and the surface of the single-mode optical fiber is coated with a titanium dioxide/silver (TBased on the surface plasmon resonance (SPR) effect, a fiber-optic refractive index sensor based on a multimode-singlemode-multimode (MSM) structure was designed. The structure of the MSM is constructed by optical fiber fusion, and the surface of the single-mode optical fiber is coated with a titanium dioxide/silver (TiO2/Ag) composite film to form a sensing unit. The effects of single-mode fiber length and metal film thickness on sensor performance were analyzed using FDTD Solutions. The results show that the longer the single-mode fiber length, the deeper the resonance depth; when the thickness of the Ag film is 50nm, and the thickness of the TiO2 film is 20nm, the sensor can obtain the best performance. In the range of 1.33~1.41 ambient refractive index, the sensor has a sensitivity of approximately 6875nm/RIU. Experimental results show that the optical fiber refractive index sensor has a simple manufacturing process and high sensitivity..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 205 (2020)
Preparation of Blue Light GaN-based Micro-LED Chips and Study on Laser Lift-off Process
WANG Xianchi, PAN Zhangxu, LIU Jiucheng, GUO Chan, LI Zhicheng, GONG Yanfen, and GONG Zheng
Based on semiconductor manufacturing process, blue light GaN-based Micro-LED chips with a size of 50μm×80μm were prepared. The forward voltage of the chips is about 2.55V. The voltage of ten LED chips under the injection current of 1mA were tested, and the maximum value of 3.24V and minimum value of 3.12V were obtBased on semiconductor manufacturing process, blue light GaN-based Micro-LED chips with a size of 50μm×80μm were prepared. The forward voltage of the chips is about 2.55V. The voltage of ten LED chips under the injection current of 1mA were tested, and the maximum value of 3.24V and minimum value of 3.12V were obtained with a fluctuation amplitude within 4%. At the test current of 1mA, the peak wavelength and FWHM of the EL spectrum of the test chips are 453nm and 14.4nm, respectively. The external quantum efficiency of the chip can reach up to 12.38%, and the chip emits very uniform light and presents a high brightness. The test results show that the prepared Micro-LED chips have excellent photoelectric performance. In addition, Micro-LED chips transfer was achieved through laser lift-off technology, and the influence of laser lift-off process on the photoelectric performance of Micro-LED chips was studied. It is found that the laser lift-off process almost has no effect on the photoelectric performance of the chips under optimized process conditions..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 211 (2020)
Study of Defect Perturbation in Reflective Field of EUV Mask Multilayer
LI Guannan, LIU Lituo, ZHOU Weihu, SHI Junkai, and CHEN Xiaomei
Extreme ultraviolet (EUV) lithography system uses a reflective mask structure with multilayers of Mo/Si, but defects can easily occur in the surface of substrate or in the process of depositing multilayer. Even a small defect can cause a large disturbance to the reflected field of mask. Manufacture of defect-free EUV mExtreme ultraviolet (EUV) lithography system uses a reflective mask structure with multilayers of Mo/Si, but defects can easily occur in the surface of substrate or in the process of depositing multilayer. Even a small defect can cause a large disturbance to the reflected field of mask. Manufacture of defect-free EUV mask is one of the most critical challenges for EUV lithography. In this paper, a multilayer structure model of ultra-ultraviolet mask with defects was established, and the influence of defect size and location on the reflection field distribution of mask multilayer structure was analyzed by finite difference time domain (FDTD) method. The results show that the interference degree of the reflection field of the multilayer structure is the result of the combination of the height and width of the defects, and is related to the smoothness of the defect structure. The interference degree of the reflection field is also related to the height of the defects in the multilayer structure. The defects that cause the multilayer structure to be deformed near the bottom have little influence on the reflection field, while the defects that cause the multilayer structure to be deformed near the top have obvious interference on the reflection field..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 217 (2020)
Design of Nonlinearity Correction of Platinum Resistance Temperature Sensor Based on Voltage-controlled Current Source
XU Ziying, DONG Feng, and FU Yutian
As a kind of temperature sensor, the platinum resistance has a wide application in many industrial sectors and fields of aerospace due to its advantage of high accuracy, long-term stability, repeatability and interchangeability. In this paper, a method of nonlinearity correction of platinum resistance is presented baseAs a kind of temperature sensor, the platinum resistance has a wide application in many industrial sectors and fields of aerospace due to its advantage of high accuracy, long-term stability, repeatability and interchangeability. In this paper, a method of nonlinearity correction of platinum resistance is presented based on a voltage-controlled current source. The method is featured in easy circuit design and parameter calculation. It was applied to an onboard radiometric calibration system, and both the corresponding circuit design and laboratory data were presented. It is shown that, the measuring error caused by the nonlinearity is reduced to 0.016℃, within a measuring range of -40~70℃..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 223 (2020)
Study on The Performance of Vapor Chamber for Near Infrared Single Photon Detector
YAO Youdan, HONG Zhanyong, and LUO Chenggang
Near infrared single photon detector is an important part of quantum secure communication, and reducing its operating temperature is the key to improve the detection efficiency. In this paper, the characteristics of temperature difference of aluminum alloy radiator and vapor chamber were discussed, the relationship betNear infrared single photon detector is an important part of quantum secure communication, and reducing its operating temperature is the key to improve the detection efficiency. In this paper, the characteristics of temperature difference of aluminum alloy radiator and vapor chamber were discussed, the relationship between the starting speed and the change of heat flux was studied, the influence of heat flow density on the thermal resistance value of the cooling device was analyzed, and a system for experimental verification was build. The results show that the cooling performance of the vapor chamber is better than that of the aluminum alloy radiator, the temperature difference can be controlled within 2℃, and the starting speed of the vapor chamber is faster. In addition, the size of the radiator has a great influence on the heat dissipation performance. When the same heat flux is loaded, the large-size vapor chamber can dissipate more heat. Therefore, the use of a larger vapor chamber will be conducive to improve the detection efficiency..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 227 (2020)
Numerical Analysis on Heat Transfer and Flow Characteristics of Grooved Microchannel
FAN Xianguang, HUANG Jiangyao, and XU Yingjie
Four microchannel models with symmetrical and equidistant grooves are proposed for the heat dissipation of electronic devices. The effects of groove shape and layout on microchannel flow and heat transfer performance under different Reynolds numbers (Re) were studied by three-dimensional numerical simulation. The resulFour microchannel models with symmetrical and equidistant grooves are proposed for the heat dissipation of electronic devices. The effects of groove shape and layout on microchannel flow and heat transfer performance under different Reynolds numbers (Re) were studied by three-dimensional numerical simulation. The results show heat transfer performance of circular groove is only inferior to that of the triangular groove, while trapezoid and rectangular grooves are poor. The pressure drop of triangular groove is the largest, followed by circular groove, and the pressure loss difference between trapezoid and rectangular groove is small, but the pressure drop is almost the same for the grooves with the same shape and different layout, which indicates that changing the groove layout to improve performance will not produce additional pressure loss. Combining with the characteristics of heat transfer and pressure drop, the thermal performance coefficient (TPC) of microchannel increases first and then decreases, so the optimal TPC is obtained with the triangular groove at Re=600, while the TPC of the equidistant circular groove exceeds that of the triangular groove at Re=900..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 232 (2020)
Optimization and Design of Omnidirectional and Broadband Antireflection Layer Based on Moth-eye Array
LIU Xiaoguang, and WANG Yuefeng
In order to reduce the reflectivity of solar cell PET packaging materials, the rigorous coupled wave analysis (RCWA) method is used to optimize the anti-reflection layer based on moth-eye array of PET film. Firstly, the solar light transmission characteristics of conical, parabolic and sinusoidal moth-eye structures arIn order to reduce the reflectivity of solar cell PET packaging materials, the rigorous coupled wave analysis (RCWA) method is used to optimize the anti-reflection layer based on moth-eye array of PET film. Firstly, the solar light transmission characteristics of conical, parabolic and sinusoidal moth-eye structures are compared. It is shown that the conical moth-eye structure has the best omnidirectional and broadband anti-reflection performance. Meanwhile, effects of geometry parameters on moth-eye array with conical structure are analyzed, which helps to select optimal parameters. On this basis, a moth-eye array based on composite structures composed of cylindrical and conicalstructure is proposed. By optimized geometry parameters, the transmittance of sunlight under large angle incident conditions is further improved. The PET film having moth-eye array with optimized composite structures has a normalized transmittance of 0.9664 for a solar wavelength with a wavelength range of 0.3~1.1μm under the incident angle of 0°~90°, which is 12.77% higher than that without taking countermeasures..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 237 (2020)
Study on Thermal Stability of Ohmic Contact of Pd/NiO/Al/Ni Reflective Electrode on p-GaN
ZUO Bingxin, ZENG Zhaohui, LI Qixin, LI Yelin, LIU Ningyang, ZHAO Wei, CHEN Zhitao, and LI Yunping
The specific contact resistance, thermal stability and optical reflectivity of the ohmic contact on p-GaN of Pd/NiO/Al/Ni reflective electrode were investigated. Compared with the traditional Pd/Al/Ni electrode, the ohmic contact of Pd/NiO/Al/Ni electrode keeps low specific contact resistance (＜5×10-4Ω·cm2) aThe specific contact resistance, thermal stability and optical reflectivity of the ohmic contact on p-GaN of Pd/NiO/Al/Ni reflective electrode were investigated. Compared with the traditional Pd/Al/Ni electrode, the ohmic contact of Pd/NiO/Al/Ni electrode keeps low specific contact resistance (＜5×10-4Ω·cm2) and high reflectivity (＞80%@365nm) after annealing at 300℃ for 10 minutes in nitrogen environment. The optimized Pd/NiO layer thickness is 1nm/2nm. Under such conditions, the Pd/NiO/Al/Ni reflective electrode can not only form good ohmic contact, but also have low specific contact resistance, reduce the absorption of UV light and maintain high reflectivity. The results show that the appropriate thickness of NiO layer can effectively prevent the infiltration of the upper layer of Al metal into the surface layer of p-GaN during annealing, which is very important for the preparation of high-quality Al-based reflective electrode..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 242 (2020)
Lift-Torque Sensor Applied for Insect-Inspired Flapping-Wing Micro Air Vehicle
MENG Ran, ZHANG Weiping, WANG Chenyang, ZHOU Sui, and WEI Mingchen
Due to high-frequency flapping motion, the insect-inspired flapping-wing micro air vehicles(FMAV)present the characteristics of flexible and large deformation, nonlinearity vibration, force-torque coupling, etc. The lift force and torque generated by IFMAV is about mN and μN·m respectively, but it is difficult to Due to high-frequency flapping motion, the insect-inspired flapping-wing micro air vehicles(FMAV)present the characteristics of flexible and large deformation, nonlinearity vibration, force-torque coupling, etc. The lift force and torque generated by IFMAV is about mN and μN·m respectively, but it is difficult to accurately test small force and torque, which brings challenges for the structure design and control of the FMAV. In this paper, a novel force-torque sensor for the IFMAV is presented, which can measure the high-frequency lift force and torque generated by the IFMAV under fixed constraints. The lift-torque senor is designed to use a symmetrical multi-cantilever compliant mechanism to convert lift force/torque into a small deformation. Combined with a high-bandwidth, high-precision capacitive displacement measuring device, it can collect data of lift force/torque under high-frequency vibration conditions. In this paper, the sensor mechanics modeling is based on the beam theory, and it is verified by finite element simulation. The structure is designed and processed based on the main parameters of the IFMAV. Experimental test indicate that such features as the lift measurement range of -10~10mN, torque measurement range of -20~20μN·m, characteristic frequency of 1kHz, and the sensitivity of lift and torque of 0.01mN and 0.01μN·m respectively, were obtained. This sensor meets the test requirements of IFMAV which weights between 80~250mg and works in the range of 1~200Hz frequency..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 247 (2020)
Preparation and Characterization of Graphene-Molybdenum Disulfide Vertical Heterojunction
GU Jie, YAN Yuankai, and WAN Xi
By using the monolayer graphene grown by chemical vapor deposition (CVD) as the conductive electrode and ammonium tetrathiomolybdate aqueous solution as the electrolyte, the vertical heterojunctions of molybdenum disulfide-graphene (MoS2/graphene) were synthesized by electrochemical deposition method. The synthesized MBy using the monolayer graphene grown by chemical vapor deposition (CVD) as the conductive electrode and ammonium tetrathiomolybdate aqueous solution as the electrolyte, the vertical heterojunctions of molybdenum disulfide-graphene (MoS2/graphene) were synthesized by electrochemical deposition method. The synthesized MoS2/graphene vertical heterojunction was annealed by chemical vapor deposition(CVD) system under the hydrogen and argon atmosphere. The Raman spectroscopy (Raman), X-ray diffraction (XRD), scanning electron microscope (SEM), and atomic force microscope (AFM) were used to systematically analyze the material composition, surface morphology, and thickness of the resulting MoS2/graphene vertical heterojunctions. This simple, environment-friendly, and low-cost method for synthesizing large-area MoS/graphene vertical heterojunctions has universal applicability, which opens a new way for the synthesis of other vertical heterojunctions..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 252 (2020)
Research on Distributed Holographic Aperture Digital Imaging Technology Based on GPU
HUANG Jiaying, YANG Feng, ZHU Lei, and RAO Changhui
Distributed holographic aperture digital imaging technology is an active imaging technology that uses digital holography to record the complex amplitude information of each sub-aperture, and realizes comprehensive imaging through phase stitching between apertures. In long-distance imaging, the high-order phase error inDistributed holographic aperture digital imaging technology is an active imaging technology that uses digital holography to record the complex amplitude information of each sub-aperture, and realizes comprehensive imaging through phase stitching between apertures. In long-distance imaging, the high-order phase error in the subaperture introduced by atmospheric turbulence, the low-order phase error between the subapertures, and the position mismatch error between the apertures will affect the imaging quality. Stochastic parallel gradient descent (SPGD) is an optimal control algorithm without wavefront detection. With the advantages of parallelism, fast convergence, high efficiency and reliability, it can be used to correct high-order and low-cost phase errors within the aperture of the system. However, the SPGD algorithm requires multiple iterations and a huge amount of calculations, which is difficult to meet the real-time requirements. In this paper, parallel acceleration processing was performed based on the GPU platform for both high and low-order phase error correction, and the operation speed is 26.42 and 36.47 times higher than the CPU platform, respectively. In addition, the AKZAE algorithm was used to correct the position mismatch error between the sub-apertures and complete the splicing of the complex amplitudes of the sub-apertures, Finally, distributed four-aperture comprehensive imaging was realized..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 257 (2020)
Multispectral Image Preprocessing Based on Elevation and Surface Feature Spectrum Constraints
FANG Xiuxiu, HUANG Min, WANG Dezhi, ZHANG Guifeng, and ZHAO Baowei
When multispectral images are generated by mosaicking and registration, they are prone to strip noise and mismatch due to the effects of clouds and water. In the paper, a combined method of images registration based on SIFT algorithm constraints to 3D information and multispectral images preprocessing algorithm under tWhen multispectral images are generated by mosaicking and registration, they are prone to strip noise and mismatch due to the effects of clouds and water. In the paper, a combined method of images registration based on SIFT algorithm constraints to 3D information and multispectral images preprocessing algorithm under the restriction of ground spectral characteristics is proposed. In this algorithm, SIFT operator constraints to 3D information are used to improve the registration accuracy. At the same time, effective radiation calibration points are selected under the ground spectral characteristics constraints to improve the gray-scale correction accuracy of each band image when stitching. The experimental results show that, when the method is used to preprocess the multispectral camera data, even if there are special areas such as clouds and water on the image, the images can own high registration accuracy without strip noise, and the spectral consistency is high..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 264 (2020)
A CO2 Detection System Based on Broadband Light Source and FP Cavity Filtering
CHENG Long, DING Lei, and ZHANG Ziru
A system based on wide-band light source and Fabry-Perot (FP) structure is introduced for the detection of CO2. The system is an active optical system with simple structure and high signal noise ratio (SNR). Based on the principles of traditional differential absorption lidar, the basic working principles of the detectA system based on wide-band light source and Fabry-Perot (FP) structure is introduced for the detection of CO2. The system is an active optical system with simple structure and high signal noise ratio (SNR). Based on the principles of traditional differential absorption lidar, the basic working principles of the detection system are described, and the system parameters are designed by using the HITRAN database to simulate the atmospheric environment. Thus the working band of the system is determined to be 1.57μm, the light source is a L-band super-luminescent LED (SLED), and the energy fluctuation value Rip is 50dB. The system output power is 24.51mW, and the filter at the receiving end is a fiber-optic FP cavity filter with the center wavelength of 1.55μm, the bandwidth of 60nm, and the channel interval of 50GHz. The error of the designed system is only 2×10-6..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 268 (2020)
Design and Verification of Light and Small Push-broom and Video Integrated Camera
HU Yongfu, XIE Jing, WU Jianfu, QI Wenwen, and MOU Yanna
Introduced is a comprehensive optimization design about light and small push-broom &video integrated cameras for micro and nano satellites. In the system design, the integrated processing of satellite and ground is considered comprehensively, the RC system with large F-number is used to reduce the volume and weightIntroduced is a comprehensive optimization design about light and small push-broom &video integrated cameras for micro and nano satellites. In the system design, the integrated processing of satellite and ground is considered comprehensively, the RC system with large F-number is used to reduce the volume and weight. Commercial shelf strengthening technology is applied to achieve high performance and reduce cost. On-board data processing adopts digital TDI technology to realize push-broom and video integrated imaging of array camera, greatly improving imaging efficiency. The designed micro/nano remote sensing camera has a variety of working modes, such as video, push-broom, strip and so on, to meet the needs of different application scenarios. This technology has been applied in the design and development of micro and nano remote sensing payload, such as the OVS-1 video camera. High quality video and remote sensing images have been obtained in orbit. It has a broad application prospect in the market of commercial remote sensing payload..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 273 (2020)
Research on Feature Detection Algorithm of Fatigue Driving Face Image Based on SVM
LIU Mengjia, and ZHAO Jianguo
Aiming at the defects of the traditional image recognition algorithm, which has poor precision and low accuracy in fatigue driving detection, an effective evaluation method of fatigue driving detection using face image data is proposed. Through real-time acquisition of the vehicle drivers face image, the face image waAiming at the defects of the traditional image recognition algorithm, which has poor precision and low accuracy in fatigue driving detection, an effective evaluation method of fatigue driving detection using face image data is proposed. Through real-time acquisition of the vehicle drivers face image, the face image was preprocessed first, the face area in the image was detected with the help of Dlib and the feature points of the face image were marked, then the eye-aspect-ratio (EAR)-based method was used to recognize the fatigue feature of the human eyes in the image, the mouth-aspect-ratio (MAR)-based method was used to recognize the fatigue feature of the mouth in the image, and finally the support vector machine (SVM) was applied to combine the two features for fatigue driving detection. Experimental results show that the method can locate the feature points accurately, and the recognition rate of fatigue detection reaches 84.29%, which can effectively identify the fatigue state..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 278 (2020)
Infrared and Visible Image Fusion Based on Two-Level Decision Rules
WANG Fanglian, and LI Xiyan
Aiming at the problem that the traditional visible and infrared image fusion methods usually present missing directional and anisotropic information in the fusion image, a two-level decision rule based infrared and visible image fusion method is proposed. This method fuses anisotropic diffusion (AD) and extreme value rAiming at the problem that the traditional visible and infrared image fusion methods usually present missing directional and anisotropic information in the fusion image, a two-level decision rule based infrared and visible image fusion method is proposed. This method fuses anisotropic diffusion (AD) and extreme value rules. Firstly, an AD filter is used to decompose each input source image into an approximation layer and a detail layer. Then, the two-level fusion decision rules are applied to the detail layer and the approximation layer, respectively, to preserve the spectral information and structural information. Finally, the structural similarity index (SSIM), average gradient (AG), and information entropy (IE) can be used to evaluate the image quality of the fused image. Experimental results show that compared with other existing image fusion methods, the fusion image of the proposed method in this paper can obtain more information and effectively reduce the artifacts, which verifies the effectiveness of the proposed method..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 283 (2020)
Design of Automated Test System for Leakage Current between Electrodes of CCD Image Sensor
GUO Li, ZHOU Jianyong, HE Da, HE Changhai, YIN Jun, TANG Zunlie, and YUAN Shishun
Leakage current between electrodes of charge coupled device (CCD) image sensors is a key parameter affecting the reliability of CCD, thus the measurement of leakage current is very important for the detection and screening in the production process of CCD image sensors. In this paper, based on an automatic test method Leakage current between electrodes of charge coupled device (CCD) image sensors is a key parameter affecting the reliability of CCD, thus the measurement of leakage current is very important for the detection and screening in the production process of CCD image sensors. In this paper, based on an automatic test method of leakage current, an automated test system for leakage current between CCD electrodes is designed. The signal name, test channel address and the test criterion can be customized according to different types of CCDs, and automated cycle scanning operations are controlled by computer software to collect leakage current data to form a standard test report automatically. This automated test system presents the advantages of flexible setting, convenient operation and automated testing, which can effectively improve the testing efficiency and equipment versatility in the production and screening processes of CCDs..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 287 (2020)
Optical Ciphertext-only Attack System for Joint Transform Correlator Encryption System
PENG Kaifei, SHEN Xueju, and HUANG Fuyu
Aiming at the problem that the numerical attack algorithms such as hybrid input-output (HIO) algorithm attack the JTC encryption system with long running time and low attack efficiency, an optical ciphertext-only attack system based on optical path iteration is designed. The system utilizes the characteristics of high-Aiming at the problem that the numerical attack algorithms such as hybrid input-output (HIO) algorithm attack the JTC encryption system with long running time and low attack efficiency, an optical ciphertext-only attack system based on optical path iteration is designed. The system utilizes the characteristics of high-speed parallel processing of optical system, and replaces the digital Fourier transform by optical Fourier transform, which significantly reduces the running time of the algorithm and effectively improves the attack efficiency. The simulation results show that compared with the HIO algorithm, the optical ciphertext-only attack system effectively reduces the running time of the algorithm and significantly improves the attack efficiency of the JTC encryption system under the same number of iterations..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 291 (2020)
Real-time Lightweight UAV Detection Method Based on SSD Algorithm
WANG Ruoxiao, XU Zhiyong, and ZHANG Jianlin
In order to solve the problem that detection algorithm of unmanned aerial vehicle (UAV) can not detect UAV quickly and accurately, an improved real-time lightweight UAV detection algorithm based on SSD is proposed, which is called TSSD. Firstly, a lightweight backbone network is improved to solve the problem of large aIn order to solve the problem that detection algorithm of unmanned aerial vehicle (UAV) can not detect UAV quickly and accurately, an improved real-time lightweight UAV detection algorithm based on SSD is proposed, which is called TSSD. Firstly, a lightweight backbone network is improved to solve the problem of large amount of weights parameters in the backbone network of SSD algorithm. Secondly, SSD only uses multi-layer feature map for multi-scale prediction, but the relationship between features is not well utilized, and a feature enhancement module is added to improve the detection ability. The experimental results of the self-built UAV dataset show that the detection speed of the proposed algorithm is 125f/s, which is much higher than that of the original SSD, and the accuracy of the proposed algorithm is also higher than that of the latter..
Semiconductor Optoelectronics
- Publication Date: Jan. 01, 1900
- Vol. 41, Issue 2, 296 (2020)
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