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Wang D.-H.,National University of Defense Technology | Niu Z.-D.,National University of Defense Technology | Zhang P.-Y.,North Night Vision Science and Technology Group Co. | Chen Z.-P.,National University of Defense Technology
Guangdian Gongcheng/Opto-Electronic Engineering | Year: 2012

Sea-sky-line detection is an important component involved in infrared image Auto Target Recognition (ATR) techniques. Through analyzing the characteristics of infrared images under sea-sky background, a fuzzy recognition algorithm is proposed based on four feature score factors. Firstly, Radon transform is performed on gradient images in order to choose sea-sky-line candidates. Secondly, fuzzy synthetical judgment is made combining information of 4 specific features. Finally, sea-sky-line recognition result is given according to the judge values. The algorithm comparison and real data test results show that this method is widely applicable, powerful in resistance to interferences and noises and has a high recognition rate, which can be used to effectively extract sea-sky-lines under complex backgrounds, thus lay a good foundation for further application such as target recognition. Source


Yang W.,North Night Vision Science and Technology Group Co.
Guangxue Jishu/Optical Technique | Year: 2014

Two kinds of thin-film with full different physic performances are combined together on K9 glass substrate to form composite film layer, achieving anti-electromagnetic interference and high light-transmitting. Technical performance index: light-average transmissivity is not less than 90% in 400 nm-1100 nm. The resistance value on anti-electromagnetic interference shielding surface is 4±0.5Ω/□ to achieve a good anti-electromagnetic interference shielding. A complex film construction composed of electromagnetic interference resistance and reducing reflecting coating is designed to meet the technical performance requirements and coating experiment is carried out. The experiment result shows that microstructure of optical thin film can be improved by ion assisted deposition technology to increase optical performance, physical performance and durability of complex thin film. Source


Liu F.,Beijing Institute of Technology | Yu Z.,Beijing Institute of Technology | Yang W.,North Night Vision Science and Technology Group Co. | Zheng H.,Chongqing Jialing Huaguang Optical Electronic Science and Technology Co. | Zhang S.,Beijing Institute of Technology
Guangxue Jishu/Optical Technique | Year: 2014

IGZO film, as the active layer of thin film transistor, is prepared by different sputter power. The film morphology and the electrical characteristics of IGZO film are measured by scanning electron microscopy and Hall effect measurement system. The instability of IGZO TFT prepared by different sputter power under gate bias stress is studied. The result shows that, in a certain range, the film prepared by lower sputter power has rough surface, more defect density and lower carrier concentration. Positive gate bias induces IGZO-TFT positive voltage threshold shift, but negative gate bias stress do not produce voltage threshold shift. Source


Lin Q.,Beijing Institute of Technology | Jin W.,Beijing Institute of Technology | Guo H.,Beijing Institute of Technology | Zhang Y.,North Night Vision Science and Technology Group Co. | Li M.,North Night Vision Science and Technology Group Co.
Guangxue Xuebao/Acta Optica Sinica | Year: 2012

Dual-band and multi-band imaging techniques get more and more attention of the national military. As a key part, dual-band optical systems, especially visible light/long-wave infrared (VIS/LWIR) wide-band imaging systems, become the focus of research. The dual-band imaging systems for several major structural forms, including reflective, catadioptric and refraction forms are analysed, and the composition and characteristics of the refraction form are introduced. For the shortcomings of the dual-band system, a VIS/LWIR common-window objective lens in the refraction form used in handheld field is designed. The system's main technical indicators are: 0.6-0.8 μm (VIS), 8-12 μm (LWIR), f́ VIS=47 mm, f́ IR=58 mm, 2ω=9.8°, F VIS=2, F IR=1.3. Design results meet all the indicators, and the image quality meets the requirements in both bands. The size of the entire optical system is about 51 mm×93 mm×136 mm, which is compact and practical. Source


Li X.,North Night Vision Science and Technology Group Co. | Yu F.,Yunnan University | Song K.,North Night Vision Science and Technology Group Co. | Qian Y.,North Night Vision Science and Technology Group Co. | And 2 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2011

This paper describes the measuring method of fluorescence for membrane layer of Na2kSb antimony-alkali compound under glass window and quartz window excited by the laser of wavelengths of 514.5 nm and 785nm. Through comparing the fluorescence intensity of Na2KSb antimony-alkali compound under glass window and quartz window respectively when excited by laser of wavelength of 514.5 nm, it is found that the fluorescence intensity of Na2kSb layer excited with wavelength of 785nm is more suitable for the analysis of membrane layer of Na2ksb antimony-alkali compound under glass window and quartz window. By excitation with the laser in wavelengths of 514.5 nm and 785nm, peak wavelengths of fluorescence spectrum of membrane layer of Na2KSb antimony-alkali compound are measured as 898nm and 872nm and the corresponding transition energy levels are 1.42eV and 1.38eV respectively. Through the analysis of fluorescence spectrum of membrane layer of Na2KSb antimony-alkali compound, it is proved that photoluminescence is an effective tool for the research of membrane layer of Na2KSb antimony-alkali compound. Besides, further increasing the control precision of components of Na 2KSb, the synthesis process, and the material structure, will further increase the sensitivity of Na2KSb multi-alkali photocathode, and consequently further improve the performance of devices. © 2011 SPIE. Source

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