Optoelectronic Technology
Co-Editors-in-Chief
Xiangzhen Chen
Zhihua FENG, Fuling ZHANG, Guangyan DONG, Wenjie HAN, Pengxiao XU, and Dongchen WANG

The current status of optical phased array lidar antenna technology at home and abroad was introduced, its basic principle and system composition expounded, and the technical scheme of cascaded silicon-based optical phased array lidar antenna was analyzed.On this basis, key technologies such as high-density low-crosstalk waveguide array technology and stacked optical phased array technology were tackled, the key technical parameters of the lidar system were obtained, and the technical problems to be solved were furtherly elaborated.At last,the application expectation of lidar was discussed.

Dec. 28, 2022
  • Vol. 42 Issue 4 267 (2022)
  • Zhipeng GONG, Zunxian YANG, and Tailiang GUO

    ZnO thin film was prepared by atomic layer deposition (ALD) and furtherly used as the carrier transport layer of thin film transistors. The phototransistor was fabricated and used in photo detection by combining the ZnO with particular CsPbBrI2 all inorganic perovskite to form hybrid film because of its excellent optical properties. ZnO thin film in the transistors could be prepared at relatively low temperature of 150 ℃ without furtherly high temperature annealing, and simultaneously the CsPbBrI2 perovskite films could also be formed by a low temperature process. The photodetector exhibited a good response to the light in a wide wavelength range between 365 nm and 600 nm. When exposed to the light irradiation of 500 nm wavelength, the optimized responsivity of 2×103 A/W and detectivity of 3×1014 Jones were achieved, respectively. The transient response of CsPbBrI2/ZnO phototransistor also delivered a rise time of 250 ms and a fall time of 200 ms, and there remained ultra-high stability in the transient behavior even after a long-time measurement.

    Dec. 28, 2022
  • Vol. 42 Issue 4 274 (2022)
  • Xinyue ZHANG, Rui LI, and Xiangchen CUI

    MoS2 nanosheets with the thickness of above 60 nm were prepared by mechanical stripping, a traditional two-dimensional material preparation method. The morphology and thickness distribution of MoS2 flakes were observed by optical microscope and atomic force microscope, and a polarization Raman test system was built. According to the 1.8 eV bandgap of MoS2 flakes, 633 nm (1.96 eV) and 458 nm (2.71 eV) lasers were selected to excite the resonance and non-resonance Raman scattering of MoS2 flakes. The Raman scattering light was coupled into a spectroscope through optical fiber to obtain the Raman spectra, and the characteristic modes in the resonance Raman spectrum were determined by Lorentz fitting. By comparing with non-resonant Raman spectrum, it was found that the Raman spectrum of MoS2 could arouse a new Raman mode in resonant state.In addition, the resonance Raman spectra and polar coordinates at different polarization angles from 0° to 360° were observed. It was found that all the modes in the resonance Raman spectra were polarization-dependent, and the ways of polarization-dependence were similar. The theoretical model of Raman tensor was also combined with the experiment, and the fitted intensity curve could almost coincide with the data points.

    Dec. 28, 2022
  • Vol. 42 Issue 4 280 (2022)
  • Jinwei ZHAO, Deming HONG, Xiongtu ZHOU, Yongai ZHANG, Chaoxing WU, Tailiang GUO, and Jianpu LIN

    The structure of Al2O3/PMMA overlapping thin films was modeled by finite element simulation method, and the effects of wave structure morphology, period, depth and PMMA thickness on the bending properties of overlapping thin films were studied, respectively. Simulation results showed that the wavy interface structure could greatly improve the bending properties of the overlapping thin film. When the wavy structure had a period of 500~1 500 nm,a depth of 600~1 600 nm and the thickness of PMMA was 6 μm, the overlapping thin film had better bending properties. Under the same conditions, the maximum stress was reduced by more than 70% compared with the overlapping thin film without the interface structure, which could effectively improve the bending performance of the encapsulated thin film. It had guiding significance for the preparation of inorganic/organic overlapping thin films.

    Dec. 28, 2022
  • Vol. 42 Issue 4 286 (2022)
  • Jing SHENG, and Liheng WANG

    An automatic target tracking system based on binocular vision was designed. After the image information was acquired by the binocular camera of the system, the Yolov5s real-time detection algorithm was used to quickly identify the target, the kernel correlation filtering method was used for target tracking, and finally the semi-global stereo matching algorithm combined with the weighted least squares method was used to measure the target depth to obtain distance information and location. After the position of the target was obtained, the speed and direction of the system were controlled, so that the system could maintain the relative orientation and set distance from the target, and realize automatic tracking. From the results, robots could replace reporters to perform real-time tracking reports of dangerous tasks, solving the safety problems of reporters.

    Dec. 28, 2022
  • Vol. 42 Issue 4 292 (2022)
  • Hui PENG, and Xiaoli FANG

    A novel sensor based on the Differential Group Delay(DGD) of FBG was proposed in this paper. The evolution of the DGD with respect to pressure was studied theoretically and experimentally. A theoretical model for pressure sensing by use of DGD was built and numerically simulation was also carried out. The experimental pressure sensitivity was 424.2 ps/MPa at 0 MPa to 0.3 MPa. Good agreements between experiment results and numerical simulations could verify the feasibility of the method.

    Dec. 28, 2022
  • Vol. 42 Issue 4 298 (2022)
  • Chong ZHANG, and Yufeng WANG

    Aiming at the problems of the traditional disturbance observation method in photovoltaic MPPT control, such as slow response speed and difficulty in maintaining stability at the maximum power point, a hypothesis method was proposed and an adaptive particle swarm optimization algorithm with changing inertia weight and learning factor was proposed for the traditional particle swarm optimization algorithm to achieve global maximum power point tracking. The assumption method mainly assumed the maximum power point through the formula, and improved the step size based on the position of the maximum power point. IPSO algorithm mainly adjusted the parameters of traditional particle swarm optimization algorithm, optimized the search order of particles, and reduced the number of iterations. Through the modeling and simulation of MATLAB/SIMULINK software, the simulation results of the hypothesis method and IPSO algorithm were obtained and compared with the traditional algorithm. The results showed that both the hypothetical method and IPSO algorithm could achieve the accurate control of PV MPPT, which was helpful for the rapid realization of PV MPPT technology and had a good application prospect.

    Dec. 28, 2022
  • Vol. 42 Issue 4 303 (2022)
  • Yuzhen SHEN, Peng ZHANG, Jun ZHANG, and Tao TANG

    An image fusion method based on the potential low-rank representation and cross bilateral filtering was proposed. Firstly, the latent low-rank representation method decomposed the source image into low-rank partial image and salient part image, calculated the weighted average of the low-rank part, and summed the salient part. Then, the calculated low-rank part and salient part were used as the input of the cross-bilateral filter, and the corresponding weight was obtained by measuring the detailed intensity. The input image was fused by the weighted average method of cross bilateral filter and smoothed by Gaussian filter to produce the first part of the image. Secondly, the source image used the CBF to obtain the fusion image, and then passed the Gaussian filtering processing to obtain the second part image. The two parts were finally weighted and summed to obtain the final fusion image. After experimental comparison, the proposed method could effectively reduce the rate of gray change of the fusion images and improve the brightness and contrast of the fusion images, which could assure the fused image better observability.

    Dec. 28, 2022
  • Vol. 42 Issue 4 311 (2022)
  • Xingming WANG, Jun YANG, Zhonghao HUANG, Peng CAI, Chunjie WANG, Can ZHANG, Xin WANG, and Guanzheng LI

    Theoretical simulation was conducted by a model for calculating amounts of liquid crystal,and experiments were carried out for each factor. The measurements for improving uniformity of cell gap were tested on some products. The experiments results showed that PS, altitude difference on array substrate and altitude difference on color film substrate were critical factors affecting uniformity of cell gap, the three factors that could affect the Cpk value of cell gap were 0.9, 0.5 and 0.8, respectively. The Cpk of cell gap could increase 0.6 by using organic on array substrate, while that couldincrease 0.9 by using XPS. The best way to reduce altitude difference among pixels was using OC, which showed that normal OC and highly flat OC could increase the Cpk of cell gap by 0.2 and 0.5, respectively.

    Dec. 28, 2022
  • Vol. 42 Issue 4 318 (2022)
  • Lijun SHENG, Zhenjun XU, and Dongxiao ZHANG

    The surface of the flip chip was coated with an extraction layer doped with nanoparticles by hot solution method, and the phosphor layer was coated on extraction layer to prepare the white LED module.The photochromatic properties of the samples were measured and analyzed by means of instruments.The experimental results showed that when the particle size of TiO2 doped particles increased from 16 nm to 46 nm, the optical efficiency amplitude of the module increased by 0.75%, the color temperature increased by 0.57%, and the color temperature uniformity of spatial angle increased from 0.869 3 to 0.87.By adjusting the doping concentration of TiO2 particles, it was found that the average color temperature of the module could rise first and then fell, and the distribution showed a trend of low edge and high middle. When the doping concentration was 0.8%, the optical efficiency of the module increased by about 5.75% and the average color temperature increased by 9.17%.The results showed that under the condition of Rayleigh scattering, the particle size had no obvious effect on the optical performance of the module. By doping a certain proportion of TiO2 nanoparticles in the optical extraction layer, the light output efficiency of the white LED module could be improved, and the spatial color temperature uniformity of the module could be effectively improved.

    Dec. 28, 2022
  • Vol. 42 Issue 4 325 (2022)
  • Guang QIAN, Kun QIAN, Xiaozhou HE, Ziyan WANG, Xiangfei CHEN, Jie TANG, Chenquan WANG, Xiaowen GU, Yuechan KONG, and Tangsheng CHEN

    Microwave photonic Transmitter/Receiver are core components for electro-optic (EO) / opto-electric (OE) conversions in the microwave photonic systems, and have been widely used in radar, electronic warfare, communication and etc. In this paper, the principle and typical products of microwave photonic Transmitter/Receiver (T/R) were introduced, and the development trend and key technologies were discussed.

    Dec. 28, 2022
  • Vol. 42 Issue 4 241 (2022)
  • Jiangnan YUE, Yuqing LI, Xinlong CHEN, Pengxiao XU, Wenjuan DENG, Xincun PENG, and Jijun ZOU

    The development of field-assisted photocathode was reviewed, and the working principle of field-assisted photocathode was introduced. Three representative cathode structures were summarized systematically, which were InP/InGaAsP/InP, InP/InGaAs and InGaAs/InAsP/InP photocathode. InP/InGaAsP/InP double heterojunction was a research highlight in field-assisted photocathode research, and this structure was mostly used in 1.3 μm field-assisted photocathode; InGaAs heterojunction structure had high sensitivity and fast response time compared with other structures, which was conducive to the application of fringe image converter tube; the photocathode with InGaAs/InAsP/InP structure provided a graded InAsP layer between InP and InGaAs, which was very beneficial to prolong the wavelength threshold. By analyzing the characteristics and applications of different structures, the development direction and difficulties of field-assisted photocathodes were discussed.

    Dec. 28, 2022
  • Vol. 42 Issue 4 248 (2022)
  • Chenhong XIANG, Shu HU, Pingyuan YAN, Chengqiang WANG, Heng LI, and Chuanxiang SHENG

    The structure of organic⁃inorganic hybrid perovskites and their corresponding solar cells were overviewed. The characteristics of ionic liquids and applications of ionic liquids in three-dimensional hybrid perovskite solar cells were summarized.And then the effects of different ionic liquids on the properties of low-dimensional layered perovskite films and devices were introduced,the applications of ionic liquids as organic spacer in low-dimensional layered hybrid perovskite solar cells were emphasized. Finally, the problems existing in the applications of ionic liquids were discussed, as well as the future research directions in this field.

    Dec. 28, 2022
  • Vol. 42 Issue 4 254 (2022)
  • Please enter the answer below before you can view the full text.
    Submit