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Formation Mechanisms and Crack Propagation Behaviors of White Etching Layers and Brown Etching Layers on Raceways of Failure Bearings 期刊论文  OAI收割
LUBRICANTS, 2024, 卷号: 12, 期号: 2, 页码: 15
作者:  
Zhang, Xiaochen;  Wu, Di;  Zhang, Yaming;  Xu, Lijia;  Wang, Jianqiu
  |  收藏  |  浏览/下载:1/0  |  提交时间:2025/04/27
The size effects of inclusions on laser induced film damage 期刊论文  OAI收割
JOURNAL OF OPTOELECTRONICS AND ADVANCED MATERIALS, 2013, 卷号: 15, 期号: 9-10, 页码: 943-947
作者:  
Han, Jinghua;  Li, Yaguo;  Fan, Weixing;  He, Changtao;  Wang, Pingqiu
收藏  |  浏览/下载:49/0  |  提交时间:2015/05/28
The spectral feature analysis of semiconductor thin disk laser (EI CONFERENCE) 会议论文  OAI收割
Optoelectronic Materials and Devices II, November 2, 2007 - November 5, 2007, Wuhan, China
作者:  
Li J.;  Wang L.-J.;  Wang L.-J.;  Ning Y.-Q.;  Li J.
收藏  |  浏览/下载:43/0  |  提交时间:2013/03/25
The semiconductor thin disk laser is a new type of semiconductor laser. This work gives the basic operation function of semiconductor disk laser  and analyses the heat effect by the experimentally measured photoluminescence spectrum of the laser chip at different pump power and different temperature. We can see that: with increasing pump power  the thermal effects of the gain material becomes seriously and causes the saturation of carrier lifetime  so the electron-hole pair created in the absorbtion layer have no enough time to rate to one of the wells  and the non-radiative recombination happens in the barrier. When the thermal effects becomes stronger  the chip will not lasing. This phenomenon is from the smaller energy offset between barrier and quantum well. We optimize the original structure design and experimental technology. A non-absorbing AlGaAs layer who is transparent to the pumping and laser wavelength is added to confine the carriers in the quantum wells. At the same time a DBR with double reflecting band is induced to improve the absorbing efficiency of the pumping light. The single QW is replaced by the three narrow QWs  This three QWs structure can add the quantum state of QW  increase the recombination probability of carriers in the QWs and reduce the heat effect. The chemical etch equipment is also improved to control the surface unevenness to be within 50 nm.  
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:36/0  |  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