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Comparison of short focal length dual-fields LWIR optical lens 会议论文  OAI收割
Xiamen, PEOPLES R CHINA, 2020-08-25
作者:  
Mei Chao;  Liang Chenguang;  Ma Yingjun;  Fei Jiaqi;  Guo Huinan
  |  收藏  |  浏览/下载:27/0  |  提交时间:2021/06/04
Advanced astigmatism-corrected tandem Wadsworth mounting for small-scale spectral broadband imaging spectrometer (EI CONFERENCE) 会议论文  OAI收割
作者:  
Lin G.-Y.
收藏  |  浏览/下载:40/0  |  提交时间:2013/03/25
Tandem gratings of double-dispersion mount make it possible to design an imaging spectrometer for the weak light observation with high spatial resolution  high spectral resolution  and high optical transmission efficiency. The traditional tandem Wadsworth mounting is originally designed to match the coaxial telescope and large-scale imaging spectrometer. When it is used to connect the off-axis telescope such as off-axis parabolic mirror  it presents lower imaging quality than to connect the coaxial telescope. It may also introduce interference among the detector and the optical elements as it is applied to the short focal length and small-scale spectrometer in a close volume by satellite. An advanced tandem Wadsworth mounting has been investigated to deal with the situation. The Wadsworth astigmatism-corrected mounting condition for which is expressed as the distance between the second concave grating and the imaging plane is calculated. Then the optimum arrangement for the first plane grating and the second concave grating  which make the anterior Wadsworth condition fulfilling each wavelength  is analyzed by the geometric and first order differential calculation. These two arrangements comprise the advanced Wadsworth mounting condition. The spectral resolution has also been calculated by these conditions. An example designed by the optimum theory proves that the advanced tandem Wadsworth mounting performs excellently in spectral broadband. 2012 Optical Society of America.  
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:27/0  |  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