中国科学院机构知识库网格
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Design and simulation of CMOS star sensor lens with large relative aperture and wide field (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Electronic and Mechanical Engineering and Information Technology, EMEIT 2011, August 12, 2011 - August 14, 2011, Harbin, China
Zhong X.; Jin G.
收藏  |  浏览/下载:60/0  |  提交时间:2013/03/25
A 50mm focal length  F/1.25  Gaussian type optical system is designed in this paper  which has 20field of view. Actual star image adding optical cross-talk effect of CMOS(Complementary Metal Oxide Semiconductor)  detector is simulated by non-sequential ray tracing in ZEMAX optical design and analysis software to evaluate its performance. The distortion relative to image spot centriod is introduced and calculated by simulated star images  which is less than 0.03% of lens in this paper. Thermal adaptability is discussed by opt-mechanic thermal analysis  which shows the RMS spot radius of marginal filed changes less than 0.7m under 10C temperature gradient  and changes less than 1m during homogeneous temperature changing from 40C to 40C. The results of analyses and simulations show the design of this lens can achieve the requirement of high precision CMOS star sensor well. 2011 IEEE.  
Thermal difference analysis and athermalization design of infrared optical system (EI CONFERENCE) 会议论文  OAI收割
Optical Design and Testing IV, October 18, 2010 - October 20, 2010, Beijing, China
作者:  
Zhang X.;  Zhang X.;  Zhang X.
收藏  |  浏览/下载:32/0  |  提交时间:2013/03/25
When infrared optical system works in a large temperature range  the thermal effect of optical lens and optical tube will produce image plane shift and lead to imaging quality deterioration. In order to eliminate the thermal aberration  the athermalization design principles of infrared optical system were introduced  and some commonly used methods of thermal difference compensation were described. Proceeding from single lens  the thermal difference caused by temperature changing was analyzed  and the relationship between temperature and focus shift was obtained. Considering optical tube thermal expansion  a set of equations to estimate the thermal difference of lens group was given. Finally  an infrared optical imaging system that can work under the temperature range of -40C to 60C was design according to athermal technique  in which a new mechanical passive temperature compensation was proposed. Through simulation  the athermalization design could make imaging plane shift the smallest. The simulation results coincided with the theoretical formula  and the design had reference value in engineering. 2010 Copyright SPIE - The International Society for Optical Engineering.  
Study on LD-pumped Nd:YAG laser cutter (EI CONFERENCE) 会议论文  OAI收割
ICO20: Lasers and Laser Technologies, August 21, 2005 - August 26, 2005, Changchun, China
作者:  
Zhang G.;  Zhang G.;  Zhang G.;  Zhang J.;  Zhang J.
收藏  |  浏览/下载:23/0  |  提交时间:2013/03/25
The theory of laser cutter and the technology neck is analyzed. We can conclude that it is almost impossible to deal with the waste thick silicon wafers which are yielded in producing silicon wafers by conventional eroding or diamond cutting  when the cutting velocity equals 100mm/min  while it is also unperfected with ecumenical laser cutter without good beam quality or precise laseroptics system. It is represented that high average power and high repetition rate laser with good beam quality and precise laseroptics system are pivotal to obtain excellent cutting effect such as thick groove depth  double-layer 0.75mm thick silicon wafer can be penetrated.. The cross section is fine and the groove is narrow  rapid cutting speed  the cutting quality meets the expecting demand.  fine kerf section without considering the effect of technique. Considering laser medium thermal lens effect and thermal focal length changing with pumping power  using plano-convex high reflectivity mirror as the back cavity mirror to compensate the heat lens influence  a /4 waveplate to compensate heat -induced birefraction  utilize the Nd:YAG self- aperture effect  more than 50 W average power 1.064 um IR output is obtained with beam quality factor (M2) equals 3.19. Through the LD-Pumped Nd:YAG laser cutter we developed with short focus length negative spherical aberration focusing lens  double axis linear step motor positioning system  suitable beam expander multiplying factor  appropriate diameter of exit beam aperture  proper repetition rate  when the cutting velocity equals 400mm/min  0.75mm thick silicon wafer can be penetrated  
Research on LD-Pumped dual wavelength Nd:YAG Laser with high beam quality for machining (EI CONFERENCE) 会议论文  OAI收割
ICO20: Lasers and Laser Technologies, August 21, 2005 - August 26, 2005, Changchun, China
作者:  
Zhang G.
收藏  |  浏览/下载:34/0  |  提交时间:2013/03/25
Considering laser medium thermal lens effect and thermal focal length changes with pumping power  conventionally  lasers are designed to operate in the middle of thermal stable zones  where the fundamental mode size is insensitive to thermal perturbation  while this method seems impossible when large fundamental mode size is required. Through self-select mode cavity  lasers are designed to work at the border of stable zone instead  where large fundamental mode size in gain media can be reached. With increase of pumping power and self-aperture mode-selective effect  mode size would grow up automatically to a certain value suitable for monomode resonance. With double 180 W pump modules  acoustic Q-switch and LBO external frequency-doubled  over 28 W which M2 equals 4.5 quasi-CW output green laser and 52W 1.064 um IR output is obtained simultaneity. With the insertion or not of the harmonic separator by footswitch  high beam quality green  IR  and green IR lasers are obtained conveniently.  
机载测深激光雷达千赫兹全固态激光器设计及特性研究 期刊论文  OAI收割
中国激光, 2005, 卷号: 32, 期号: 9, 页码: 1197, 1201
马惠军; 李小莉; 朱小磊; 陆雨田
收藏  |  浏览/下载:1534/315  |  提交时间:2009/09/18
超强超短激光时空质量提升技术研究 学位论文  OAI收割
作者:  
吴分翔
  |  收藏  |  浏览/下载:31/0  |  提交时间:2018/12/26