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	Laser cleaning of neutral attenuator plate based on low power laser diode (EI CONFERENCE) 会议论文 OAI收割 2nd International Conference on Energy, Environment and Sustainable Development, EESD 2012, October 12, 2012 - October 14, 2012, Jilin, China 作者: Chen Y.; Li L. 收藏 \| 浏览/下载：31/0 \| 提交时间：2013/03/25 Laser cleaning is a non-contact green and environmental cleaning method which can effectively remove particulate contaminations of sizes as small as 0.1 m without damage to the optics. But most laser cleaning devices are large and heavy also expensive due to using large lasers such as CO2 laser YAG Laser etc. In this work a low power LD was tried to clean fingerprint and dust contaminated on the surface of the attenuator glasses plates. In the laser cleaning experiment with low power diode the fingerprint grease can be efficient to be cleaned but there is no evident effect for cleaning inorganic dust. The cleaning different degree of fingerprint contaminations was investigated at the variable laser parameters including laser power and irradiation time. An optical microscope was used to analyze the cleaning effect. The results show that low power LD can effectively remove the fingerprint on the surface of absorptive-type attenuator glass plates. On the premise that the attenuator optics glasses are not damaged the cleaning area increases with the increase of radiation time and laser power. The cleaning area doesn't change much with the variation of laser frequency when the other parameters are the same. (2013) Trans Tech Publications Switzerland.
	High beam quality all-solid-state 1053nm nd: Glass amplifier shaping by LCSLM at repetition frequency (EI CONFERENCE) 会议论文 OAI收割 2nd International Conference on Optical, Electronic Materials and Applications 2012, OEMA 2012, May 25, 2012 - May 26, 2012, Chongqing, China 作者: Zhang X.; Qiu J.; Zhang X.; Zhang X. 收藏 \| 浏览/下载：77/0 \| 提交时间：2013/03/25 A laser amplifier of LD pumping Nd: glass with a high beam quality and stability the modulation degree near field is less than 1.23:1. (2012) Trans Tech Publications which amplifies nanosecond laser pulse Switzerland. has been developed in this paper. Under 1Hz repetition frequency when the flat top pulse of 3 ns width and 1 nJ energy is injected as the seed pulse the average output energy of the laser amplifier is 115.3 mJ with a net gain of 109 the energy dispersion degree of the outputting laser is no more than 2%
	Analysis of laser jamming to satellite-based detector (EI CONFERENCE) 会议论文 OAI收割 International Symposium on Photoelectronic Detection and Imaging 2009: Laser Sensing and Imaging, June 17, 2009 - June 19, 2009, Beijing, China 作者: Guo L.-H.; Guo R.-H.; Wang S.-W. 收藏 \| 浏览/下载：29/0 \| 提交时间：2013/03/25 The reconnaissance satellite communication satellite and navigation satellite used in the military applications have played more and more important role in the advanced technique wars and already become the significant support and aid system for military actions. With the development of all kinds of satellites anti-satellite laser weapons emerge as the times require. The experiments and analyses of laser disturbing CCD (charge coupled detector) in near ground have been studied by many research groups but their results are not suitable to the case that using laser disturbs the satellite-based detector. Because the distance between the satellite-based detector and the ground is very large it is difficult to damage it directly. However the optical receive system of satellite detector has large optical gain so laser disturbing satellite detector is possible. In order to determine its feasibility the theoretical analyses and experimental study are carried out in the paper. Firstly the influence factors of laser disturbing satellite detector are analyzed in detail which including laser power density on the surface of the detector after long distance transmission and laser power density threshold for disturbing etc. These factors are not only induced by the satellite orbit but dependence on the following parameters: laser average power in the ground laser beam quality tracing and aiming precision and atmospheric transmission. A calculation model is developed by considering all factors which then the power density entering into the detector can be calculated. Secondly the laser disturbing experiment is performed by using LD (laser diode) with the wavelength 808 nm disturbing CCD 5 kilometer away which the disturbing threshold value is obtained as 3.5510-4mW/cm2 that coincides with other researcher's results. Finally using the theoretical model the energy density of laser on the photosensitive surface of MSTI-3 satellite detector is estimated as about 100mW/cm2 which is largely exceed the disturbing threshold and therefore verify the feasibility of using this kind of laser disturbing the satellite-based detector. According to the results. using the similar laser power density absolutely saturate the requirements to laser disturbing satellite-based detector. If considering the peak power of pulsed laser even decrease laser average power it is also possible to damage the detector. This result will provide the reliable evidences to evaluate the effect of laser disturbing satellite-based detector. 2009 SPIE.
	High power diode laser with beam coupling (EI CONFERENCE) 会议论文 OAI收割 Optoelectronic Materials and Devices III, October 27, 2008 - October 30, 2008, Hangzhou, China 作者: Wang L.; Liu Y.; Wang L.; Liu Y.; Liu Y. 收藏 \| 浏览/下载：59/0 \| 提交时间：2013/03/25 As the increasing applications of the semiconductor lasers in the laser processing the single 2-D stack optic-power density has not satisfied the actual requirements. It demands to couple several diode laser stack beams to one to improve the brightness and it becomes the central issue to adopt the appropriate beam coupling technology which would offer high quality and high efficiency. In this paper it mainly introduces the beam shaping and the technology of spatial coupling polarization coupling and wavelength coupling. The coupling key elements are presented and indicated. Finally the development of the diode laser on beam coupling in our country fell behind through analyzing the statement of the world. Our lab is studying on polarization coupling and wavelength coupling. We gain some results by phase which the polarization coupling efficiency can achieve 90% for two LD stacks with seven bars whose luminous wavelength is 975nm and980nm.By two 808nm diode laser coupling the efficiency of 60% can be achieved after focusing to the beam size of 22mm2. 2008 SPIE.
	Analysis of spectrum narrowing of diode laser bar (EI CONFERENCE) 会议论文 OAI收割 Semiconductor Lasers and Applications III, November 12, 2007 - November 13, 2007, Beijing, China 作者: Liu Y.; Wang L.; Wang L.; Wang L.; Liu Y. 收藏 \| 浏览/下载：18/0 \| 提交时间：2013/03/25 Laser diode bar (LDB) are used increasingly often for many applications but spectral bandwidth of LDB are generally approximately 2-4nm far too wide for many demanding applications e.g. spin-exchange optical pumping terahertz generation and lidar. External-cavity feedback can improve the spectral properties of LD or LDB. However spectrum narrowing of LDB is more difficult than that of LD. Bar curvature (i.e. "smile") produced in the manufacturing process affects the spectrum narrowing greatly. By geometrical optics approach and ORIGIN software smile which can be corrected by plano-convex cylindrical lens is simulated and the result is in good agreement with experiment. The selection of grating which is also a critical factor of spectrum narrowing will be stated. Finally an external cavity consisting of fast axis collimator two plano-convex cylindrical lens and a diffraction grating is used. The scheme is implemented on a 19-element LDB and yields 3-fold reduction in spectral linewidth under the situation that all optical elements in the system which are not optimized. Further we use a slit in the experiment and analyze the spectrum narrowing of each element in LDB.
	All-solid-stated laser controller design based on digital optical feedback (EI CONFERENCE) 会议论文 OAI收割 Lasers in Material Processing and Manufacturing II, November 10, 2004 - November 12, 2004, Beijing, China 作者: Liu L.; Wang J.-L.; Wang J.-L.; Liu L. 收藏 \| 浏览/下载：28/0 \| 提交时间：2013/03/25 The new design about a CW digital all-solid-stated LD pumped Nd:YVO 4 controller is introduced. The stable output power of this digital laser controller which adopts Digital Signal Processor(TMS320C31) is approximately 20mW. The whole system is composed of constant- current source protection circuit pulse-width modulation circuit Si-photo-detector and amplified circuit and Digital Signal Processor control system etc. In terms of error deviation Based on nonlinear control curves of LD power output by Si-photo-detector the region control can be obtained by means of the PID control algorithm in the software platform that is error amendment and high stability laser power output can be achieved. And the precision of temperature control can reduce from 0.2C to 0.04C. By adopted integral separated mode PID control algorithm the LD output power instability ( %) down to 2%. By way of adopting the new digital design the work to protect the laser diode including the continuous adjustable output power with high accuracy and stability is easily obtained. The internal-external modulation control of the laser power based on digital optical feedback can be accomplished with stable power output. At last the bringing reasons of noise are analyzed and the solving methods are put forward in this paper.
	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
	国产LD_2铝合金管模拟北京正负电子对撞机束流管道的抽气实验期刊论文 OAI收割真空, 1985, 期号: 1, 页码: 41-45 作者: 刘志满; 林绍鸾; 侯正义收藏 \| 浏览/下载：14/0 \| 提交时间：2015/12/14 LD_2 铝合金管高能物理研究模拟电子挤压成形质子同步加速器除气真空度真空容器实验段