Optoelectronic Technology
Co-Editors-in-Chief
Xiangzhen Chen
[in Chinese]

Jan. 01, 1900
  • Vol. 39 Issue 1 1 (2019)
  • ZHOU Fengjie, KONG Yuechan, GU Xiaowen, and NIU Bin

    The filter characteristics of the through port in single-ring and double-ring resonators based on silicon-on-insulator were researched, and the influence of the coupling coefficient between the straight-ring waveguide and the coupling coefficient between the ring waveguides on output characteristics were analyzed. An improved coupling structure using the Mach-Zehnder interferometer (MZI) in the coupling region of the resonator was proposed. In the single-ring and double-ring filters with a microring cavity length of 1 218 μm, the resonators were tuned from under-coupled state to the critical-coupled state in the power range of 19 mW and 9 mW, respectively. Moreover, the filter profile of the double-ring filter was tuned for one free spectrum range (FSR) when the heating power was 26 mW.

    Jan. 01, 1900
  • Vol. 39 Issue 1 4 (2019)
  • KUANG Wenjian, JIA Wenbo, LIU Xuefeng, Shi Haosong, LIU Hanming, and CHEN Xiaodan

    Solar-blind ultraviolet schottky barrier photodetectors based on colloidal ZnS quantum-dots were fabricated by solution processing. The cubic ZnS quantum-dots have an average particle size of 2.2 nm, and the bandgap was found to be 4.53 eV (~3.68 eV for bulk cubic ZnS). The photodetector showed an effective photoresponse for the solar-blind ultraviolet (UV) radiation. An on/off ratio of 9.2, responsivity of 1.60 mA/W and detectivity of 5.51×109 cm Hz1/2 W-1 were obtained under 254 nm radiation of 0.1 mWcm2, when operated at a bias voltage of 15 V. The response time of this device was of the order of 1 second, limited by the high resistance of the device. The results indicate that the photodetector using 2 nm ZnS quantum-dots is a promising candidate for solar-blind UV sensing.

    Jan. 01, 1900
  • Vol. 39 Issue 1 10 (2019)
  • LIN Jintang

    Field emitters with excellent field emision properties based on suspended reduced graphene oxide (rGO) layer supported by tetrapod-like zinc oxide (T-ZnO) nanostructure were proposed. The T-ZnOs were transferred onto silver electrodes by screen-printing. Then, continuous and floating rGO films were deposited on the T-ZnO layer by spin-coating. The T-ZnO/rGO emitters exhibited field emission performances with higher emission current density and lower operation voltage when compared with the pure T-ZnO emitters. The results show that the T-ZnO/rGO emitters exhibited field emission properties with a turn-on field of 2.5 V/μm (current density as 10 μA/cm2) and a threshold field of 3.8 V/μm (current density as 1 mA/cm2).

    Jan. 01, 1900
  • Vol. 39 Issue 1 16 (2019)
  • FU Haishi, PENG Hao, ZHANG Xiaodong, and ZHANG Shengdong

    The fabrication of self-aligned top gate a-IGZO TFT with source-drain doped by hydrogen diffusion was studied. The doping of hydrogen was achieved during the growth of SiNx passivation layer by PECVD. The experimental results show that the performance of the device is greatly affected by the option for the gate dielectric etching following the gate electrode patterning. For the devices with gate dielectric layer etched, it is found that the leakage current is large, which may be caused by the etching residue on the side wall of active layer; The VTH of short channel devices is negative and the mobility decreases after annealing, which is caused by the deep H lateral diffusion. For the devices without gate dielectric layer etched, it is found that the VTH of devices is positive, because of the suppression of H lateral diffusion thanks to the inhibiting effect of SiO2 gate dielectric on H doping.The on-state current and mobility of devices increases after annealing, which may be due to the entrance of H in gate dielectric to the source and drain area by thermal diffusion, reducing resistance of source and drain area.

    Jan. 01, 1900
  • Vol. 39 Issue 1 21 (2019)
  • GUO Huijie

    An enhanced algorithm on iris image quality assessment was proposed. For the disturbed iris images captured by the iris recognition system utilized for long-distance moving iris recognition, the quality indices of the resolution, availability, and contrast of the region of interest of the single frame iris image were quantified. And the joint weighted quality scores of sequential images were calculated, which were used to effectively evaluate the usability of iris image sequences and screen out the unqualified low-quality iris image sequences. Experiments show that the algorithm improves the accuracy and reliability of image quality assessment of the iris recognition system, which can effectively improve the robustness and recognition efficiency of the system.

    Jan. 01, 1900
  • Vol. 39 Issue 1 26 (2019)
  • HUANG Xiaogang, YE Lei, XU Fei, LI Zhongliang, and YANG Bin

    The structure of airborne TFT-LCD and the temperature characteristics of LC materials were analyzed. The phenomena and principles of macula which easily appeared in the high temperature environment of the LCD were studied. The heat conduction characteristics of the airborne TFT-LCD were analyzed. Two optimization schemes were proposed and analyzed by finite element method, after data comparison and analysis, the better one was selected for experimental verification. The experiment shows that the improved scheme could effectively optimize the heat dissipation structure and reduce the working temperature of LCD at high temperature.

    Jan. 01, 1900
  • Vol. 39 Issue 1 30 (2019)
  • YANG Jie, XU Pengxiao, CHI Chen, and ZHAO Wenjin

    Gated micro-channel plate photomultiplier tube is a kind of photomultiplier tube with gated function. The detector module using this device can select the desired signal from the strong background light, and can also eliminate possible damage to itsself by strong laser. This detector can be widely used in nuclear physics detection, satellite laser ranging, time-dependent fluorescence afterglow measurement and other fields. External gated micro-channel plate photomultiplier tube modules were successively developed, and the key technical issues such as the lifting of pulsed peak current, the optimization of noise induced by gate pulse and the realization of high electron gain were also solved. The detector module is preliminarily applied to the measurement of CSNS counter-angle white light neutron source, and its gating test function is realized.

    Jan. 01, 1900
  • Vol. 39 Issue 1 34 (2019)
  • JIANG Tao, ZHAO Hongwei, CAO Yun, WANG Fukang, and ZHAO Qian

    Aiming at rapidly obtaining the working status information of the display and meeting the application requirement of health monitoring management on the system level. A display with periodical working status monitoring was designed to achieve real-time status display function by using the on screen display technology and to support information reporting. Therefore, the display shows good customization and extensibility.

    Jan. 01, 1900
  • Vol. 39 Issue 1 39 (2019)
  • WU Wei, FANG Shengjiang, CHI Chen, and LIU Delin

    According to the requirements of gate-control circuit in range-gated low-light-level ICCD components and underwater high-speed imaging components a high accuracy and low jitter synchronous pulse control technique based on FPGA fine adjustment unit IODELAY was proposed to solve the synchronization and the jitter problem between the output pulse and the external trigger. This unit has the advantage of small temperature effect and high time resolution, which fully meets the requirements of the gated-control time precision and jitter of the image tube in the component. This technology has good application in all kinds of gate control components.

    Jan. 01, 1900
  • Vol. 39 Issue 1 43 (2019)
  • JIANG Mingxiao, WANG Dan, QIU Yun, SUN Xiao, QI Yonglian, HU Weipin, and BU Qianqian

    Quantum dots was a kind of new fluorescent material with wide absorption, narrow full width of half maximum and high quantity yield, fluorescence quantum efficiency. Studying on the application of quantum dots material would be helpful to realize high color gamut and ultrathin display screen. Multiple applications of the photoluminescence quantum dot and electroluminescence quantum dot in display were introduced, and the technical principles of display technology using QD-backlight, QD-CF, QLED were elaborated as well. The characteristics and development of different technologies were also analyzed. With the development of high color gamut in display, quantum dot materials will not only be widely used in LCD, but also be a powerful substitute for organic light-emitting materials. In the future, active light-emitting AMQLED display will develop synchronously with AMOLED and become the mainstream of the market.

    Jan. 01, 1900
  • Vol. 39 Issue 1 48 (2019)
  • ZHANG Jun, LI Peihua, ZHANG Sheng, and JI Tao

    The Boosting lifting model was analyzed. A selection criterion for the ratio of the mean square error and the entropy of the image after the defogging, and the different kinds of different defogging algorithms were sort out. According to the set the threshold, the appropriate defogging algorithm was selected as the "extreme best intensifier" from the multiple defogging algorithm. By optimizing the learning rate, the weight of the "optimal enhancer"was updated.A linear combination to construct an optimal fog removal algorithm was exopted was adopted. Experiments show that the algorithm achieves the balance between image contrast and image loss after fog removal. The image contrast is enhanced, the image details are highlighted, and the loss of image information is reduced to the greatest extent.

    Jan. 01, 1900
  • Vol. 39 Issue 1 52 (2019)
  • QIN Dandan, and XIA Zhiqiang

    Projected capacitive touch panels are widely used in mobile terminals. This paper introduced the principles and structures of common touch panels, focusing on the development of full In-cell technology. Full In-cell touch panels were realized by embedding touch IC into LCD IC, which can decrease the thickness of the module, and will become the mainstream. The 13.46 cm a-Si full In-cell touch panels were produced. Touch lines and data lines were set at the same layer. Organic layer and metal3 layer were omitted. Compared with the developed technology, two masks were saved at least. The costs reduces and the process is simplified. The touch frequency is 120 Hz. The key touch performances such as accuracy, precision, linearity and jitter can reach the industrial standards. The optical and reliability performances are comparable with the non In-cell pands.

    Jan. 01, 1900
  • Vol. 39 Issue 1 58 (2019)
  • YAO Jiajun, SHENG Hejun, and SONG Jianlong

    Based on the technology of the JAS film TFT-LCD pixel structure, the pixel voltage crosstalk effects of different panel inversion modes on the two kinds of JAS and non-JAS module were compared by analyzing the experiments. The results show that crosstalk has nearly no effect on the pixel voltage of the non-JAS under different inversion modes. The solution of the color crosstalk problem caused by the parasitic capacitance (Csd) between the data line and the TFT drain electrode was proposed. These results have some guiding effect to solve the pixel voltage crosstalk problem and the pixel structure design of the large size and high resolution TFT-LCD products.

    Jan. 01, 1900
  • Vol. 39 Issue 1 63 (2019)
  • LI Chengyong, and Hu Jingjing

    Using the sensor of laser obstacle avoidance and pixy visual sensor as the collector of road information, an intelligent vehicle system of photoelectric “searching” was designed, which could start from the designated position and quickly search for beacon lights that were randomly lighted in the site. The system used the pixy visual sensor to collect the light source, and got the position signal of the smart vehicle. The laser obstacle avoidance sensor was adopted to collect the position signal of the obstacle. Through PID control algorithm, path identification algorithm and speed control algorithm, the road was judged as straight line or curve. The vehicle could avoid obstacles and realize automatic driving. The system has been proved to be small size, low cost, high accuracy, high reliability and fast reaction.

    Jan. 01, 1900
  • Vol. 39 Issue 1 68 (2019)
  • Please enter the answer below before you can view the full text.
    Submit