Optoelectronic Technology
Co-Editors-in-Chief
Xiangzhen Chen

Apr. 21, 2020
  • Vol. 40 Issue 1 75 (2020)
  • Apr. 22, 2020
  • Vol. 40 Issue 1 76 (2020)
  • Wenjie HAN, Guangyan DONG, Fengchao PENG, Limei DU, Shangbing HUANG, and Chen CHI

    The developing status,operating principle and technological superiority of streak tube LIDAR were introduced in the first place. Aiming at detection of target and surroundings under water,the parameters of LIDAR system were calculated,based on which a streak tube LIDAR prototype was developed. A number of multiple dimension images were acquired by means of test and experiment,and the optimizing method was presented for later work after the detector performance of prototype was evaluated. At last,the LIDAR application expectation was discusssed.

    Apr. 22, 2020
  • Vol. 40 Issue 1 1 (2020)
  • Wei XIONG, Laifu GUAN, Lei TONG, Chuansheng WANG, Min LIU, and Chunyan ZENG

    In order to solve the problem of road extraction information loss in remote sensing images, a road extraction algorithm based on residual neural networks was proposed. Firstly, an encoder-decoder network was constructed, combined with pre-coder and dilated convolution module to extract more semantic information.Secondly, the parallel designed dilated convolution module was added to the middle part of the encoder-decoder structure, which could extract features of different receptive field features. Finally, the encoder-decoder used jumper to perform multi-scale feature fusion, learning more low-dimensional and high-dimensional features.In the Massachusetts road dataset, this method had 11 %, 0.3 %, and 7.4 % improvement in Precision, Recall, and F1-score performance indicators. At the same time, it also achieved 97.9 % in the Accuracy index. Compared with other algorithms, the algorithm has certain application value.

    Apr. 22, 2020
  • Vol. 40 Issue 1 6 (2020)
  • Yan WANG, Dongchen WANG, Pengxiao XU, Guanghua TANG, Guoqing YOU, and Yuechan KONG

    To solve the problem of practical light source lacking in silicon photonic integrated circuit, design and preparation method of integrated module including 1.55 μm InP FP laser chip, InP PIN photodetector chip and silicon optical waveguide was proposed. Silicon edge coupler of inverted cone type was fabricated by CMOS compatible process, and the coupling efficiency was 36.7 %. The laser chip and silicon waveguide chip were coupled by micro-assembly alignment technology, and the coupling efficiency was 35.8 % after UV adhesive curing. The 1 dB alignment tolerance was 1.2 μm horizontally and 0.95 μm longitudinally.

    Apr. 22, 2020
  • Vol. 40 Issue 1 13 (2020)
  • Lingling HUANG, Xingfu CHEN, Peng HU, Bo LI, Xianghua WANG, and Juntao HU

    In order to investigate the relationship between carrier mobility and crystal morphology of semiconductor thin films, the p-type conjugated organic small molecule 2,7 dioctyl [1] benzothieno [3,2-b] [1] benzothiophene (C8-BTBT) was adopted as the active layer of bottom-gate top-contact organic thin film transistor (OTFT), three kinds of processes, and dip-coating, ink-jet printing and vacuum evaporation, were used to prepare the C8-BTBT film. The growth behavior and crystallization of small organic molecules and their effects on the properties of OTFT devices varied with different processes. In addition, the effect of annealing treatment on crystallization of C8-BTBT was studied by XRD measurements. The results show that the films deposited by evaporation have higher crystallinity, high substrate coverage, and exhibit the Stranski-Krastanov (SK) growth mode, and the trap density of the corresponding device is the lowest, so that the mobility is as high as 5.44 cm2·V-1·s-1 and the on/off is more than 106. In addition, annealing could severely destroy the crystallization of C8-BTBT. Therefore, controlling the growth behavior of the semiconductor layer, therefore improving the coverage and crystallinity of the semiconductor layer is an effective way to fabricate high performance conjugated small molecule OTFT devices.

    Apr. 21, 2020
  • Vol. 40 Issue 1 28 (2020)
  • Haikuan MA, Shuwei ZHANG, Ning WU, Dongzhi CHU, Xuan CAO, Xiangfeng KONG, Ran MA, and Fengqing LIU

    Marine plankton imaging technology plays an important role in the study of Marine ecosystem, and has great significance to fishery production and basic research of Marine science. In order to adapt to the observation of Marine plankton, a zoom micro-optical system with large relative aperture made for underwater plankton observation was designed. The imaging environment simulated seawater medium and this system was designed by Zemax software. The system used a 8.8 mm×6.6 mm CCD camera, and the imaging system multiplier were 1, 2, 4, respectively. The numerical aperture remains 0.15 during the process of changing times. The field of view was 8 mm×6 mm~2 mm×1.5 mm. At the maximum field of view, the optical transfer function (MTF) of near-axial field of view and 1 field of view at Nyquist frequency 50 lp/mm was both greater than 0.4, and the distortion of the imaging system was controlled within 3%. The microscopic imaging system structure is simple, and can satisfy the plankton imaging of small size, providing the analysis of the plankton and phytoplankton population research with technical support.

    Apr. 22, 2020
  • Vol. 40 Issue 1 35 (2020)
  • Xiaogang HUANG, Lu WANG, Zhongliang LI, Guobing ZHENG, Bin YANG, Yiyou HONG, and Yinglu FANG

    Through the analysis of organic polymer materials′ aging mechanism for TFT-LCD, the main stress and the weak links of tapes and adhesives during storage and usage were studied, respectively. The aging test methods and failure evaluation indexes of organic polymer materials at different stages were proposed and tested, which could support the life evaluation of organic polymer materials for TFT-LCD.

    Apr. 22, 2020
  • Vol. 40 Issue 1 39 (2020)
  • Changbing QIN, Qihong CHEN, Tingting XU, Baixue ZHANG, and Jianbing YANG

    In order to improve the gray-scale characteristics when the traditional analog driving scheme is dimmed, a PWM circuit for silicon-based OLED driving chip has been presented. The circuit could modulate the common cathode voltage applied to the OLED array with PWM, so as to achieve the same gray scale characteristics when adjusting brightness. The circuit was designed and verified by the 0.18 μm mix-signal 1P6M CMOS process. Simulation and test results show that when the brightness is adjusted from 100 cd/m2 to 500 cd/m2, the gray-scale characteristics could be significantly improved.

    Apr. 22, 2020
  • Vol. 40 Issue 1 44 (2020)
  • Chen SHENG, Zhile YIN, Guangming TANG, and Qiubai YAN

    The forced air-cooling strategy for the rugged display was chosen based on the applied external environment and the thermal characteristics of the internal function modules. The thermal simulation was applied to guide the fan type selection and verify the feasibility of the proposed heat dissipation strategy. The accuracy of the simulation results were validated by the hardware experiments,providing a novel approach for the thermal design of the rugged display.

    Apr. 22, 2020
  • Vol. 40 Issue 1 48 (2020)
  • Jun WANG, Jian SHEN, Jun QU, Wei ZHANG, and Song ZHAO

    A special liquid crystal display backlight module based on U-shaped light guide plate was presented to reduce the thickness of side-in backlight module.Firstly, the curved side backlight module with 1 mm and 2 mm U-shaped light guide plate was designed and modeled by LightTools software. Then, two different thickness curved side backlight modules and a side-in backlight module with 4 mm conventional flat plate light guide plate were simulated and compared. Finally, the relative shifting simulation of the curved side backlight module with 2 mm U-shaped light guide plate was carried out and the results showed that the optical performance of the module had high stability in the strong vibration and wide temperature environment. Compared with the conventional side-in backlight module, the proposed curved side backlight module with 2 mm U-shaped light guide plate maintained the consistency of optical performance,which had certain reference significance for the thin design of special display.

    Apr. 21, 2020
  • Vol. 40 Issue 1 52 (2020)
  • Jianjun CHEN, Lei LI, Hongwei ZHAO, Kaili LIU, and Li ZHAO

    A LED backlighting dimming method based on PDM algorithm was proposed in order to solve the defect of PWM dimming method in application.The frequency domain simulation analysis of waveforms showed that the harmonic frequency of PDM method moved to higher region than PWM method, avoiding the test frequency band(25 Hz~10 kHz)of CE101 so that it was easier to pass the EMC CE101 test with PDM method. As a result, compared with PWM method, the current waveforms were relatively gentle and the load characteristics were obviously improved by using PDM method. In summary, PDM method has advantages in electromagnetic environment and load sensitive applications.

    Apr. 22, 2020
  • Vol. 40 Issue 1 57 (2020)
  • An improved temperature compensation method based on software compensation combined with constant current source compensation was studied. Hardware circuits were used by this study,such as single-chip microcomputers, constant current sources, digital temperature sensors and multipliers to optimize traditional software compensation.The compensation effect was better than traditional constant current.The source compensation has been significantly improved, and the overall "temperature drift" has dropped about 13.7 %. The traditional temperature compensation methods,such as thermal element compensation, constant current source compensation and software compensation,were also supplemented. It was of great significance to improve the accuracy of Hall current sensors and meet the actual production requirements.

    Apr. 21, 2020
  • Vol. 40 Issue 1 63 (2020)
  • An acousto-optic control system was designed for expelling birds, which took the STM32 microprocessor as the core to build the hardware control system,and the implementation of hardware circuit was given.To solve the problem of bird adaptability, the function of switching different gear positions was designed. In order to verify the performance of the system, the measured LED spot area was divided into equal areas, and its illumination was tested.The results showed that the illumination of the designed system could reach more than 200 Lx, which could provide a reference for designing a new type of bird repellent system.

    Apr. 21, 2020
  • Vol. 40 Issue 1 70 (2020)
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