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浏览/检索结果: 共5条，第1-5条 帮助 限定条件 内容类型：会议论文    专题：长春光学精密机械与物理研究所    第一署名单位    第一作者单位    通讯作者单位     已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择作者升序作者降序题名升序题名降序发表日期升序发表日期降序提交时间升序提交时间降序 Effect of adding Cr on magnetic properties and metallic behavior in MnTe film (EI CONFERENCE) 会议论文 Wang Z. H.; Geng D. Y.; Gong W. J.; Li J.; Li Y. B.; Zhang Z. D. 收藏  |  浏览/下载：35/0  |  提交时间：2013/03/25 Mn1 - xCrxTe films with x = 0  0.02  and 0.05 was synthesized by pulsed laser deposition and crystallize in hexagonal NiAs-type structure. The spin glass behavior predicted before by Monte Carlo calculation is observed in the MnTe film. This behavior is destroyed by adding Cr in the MnTe film. The temperature dependence of magnetization shows a sharp rise at around 66 K  due to the magneto-elastic coupling. Metallic behavior is observed in the MnTe film in the temperature range 120-220 K  which is ascribed to the magnetic ordering. The metallic behavior disappears with adding Cr  because adding Cr ions destroys the magnetic ordering which is mediated by the sp-d exchange interaction between the Cr ions. 2012 Elsevier B.V.   Experiments of second harmonic generation output in pulsed TEA CO 2 laser (EI CONFERENCE) 会议论文 High-Power Lasers and Applications V, October 18, 2010 - October 19, 2010, Beijing, China Guo R.; Li D. 收藏  |  浏览/下载：40/0  |  提交时间：2013/03/25 It is always the hot subject to realize the output of high-power laser in the range of 3-5m wavelength. This rang of wave band has greatly important applications in military because it located in the atmosphere window. Generally there are two ways to obtain this range of laser wavelength. One way is through optical parameter oscillation (OPO) from shorter laser wavelength and the other is through second harmonic generation (SHG) from longer laser wavelength. Firstly  the comparison between tow nonlinear crystals ZnGeP2 and AgGaSe2 is conducted for their nonlinear coefficient and damaging threshold in theory. The theoretical results show that the crystal AgGaSe 2 is more suitable for the SHG of pulsed TEA CO2 laser. When using pulsed TEA CO2 laser with wavelength of 9.3m to pumping AgGaSe2 SHG crystal  the wavelength of 4.65m is obtained. In the condition of repetition rate 100Hz  the upmost output power of single pulse is up to level of 1W  which corresponding efficiency of SHG is about 6%. The experimental results show that the polarization of laser beam has greatly influence on the SHG output of the crystal. Under the radiation of 3MW/cm 2 from fundamental wave and the right position for maximal SHG output in the crystal  when polarization of laser beam rotates 4.5  the SHG output of energy decrease about 30%. The research of this paper will make a foundation for further development of mid-infrared laser. 2010 Copyright SPIE - The International Society for Optical Engineering.   Analysis of laser jamming to satellite-based detector (EI CONFERENCE) 会议论文 International Symposium on Photoelectronic Detection and Imaging 2009: Laser Sensing and Imaging, June 17, 2009 - June 19, 2009, Beijing, China Wang S.-W.; Guo L.-H.; Guo R.-H. 收藏  |  浏览/下载：16/0  |  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.   Large aperture low threshold current 980nmVCSELs fabricated with pulsed anodic oxidation (EI CONFERENCE) 会议论文 Optoelectronic Materials and Devices II, November 2, 2007 - November 5, 2007, Wuhan, China Jinjiang C.; Yongqiang N.; Te L.; Guangyu L.; Yan Z.; Biao P.; Yanfang S.; Lijun W. 收藏  |  浏览/下载：19/0  |  提交时间：2013/03/25 Pulsed anodic oxidation technique  a new way of forming current blocking layers  was successfully used in ridge-waveguide QW laser fabrication. We apply this method in 980nm VCSELs fabrication to form a high-quality native oxide current blocking layer  which simplify the device process. A significant reduction of threshold current and a distinguished device performance are achieved. The 500m-diameter device has a current threshold as low as 0.48W. The maximum CW operation output power at room temperature is 1.48W. The lateral divergence angle //and vertical divergence angle are as low as 15.3 and 13.8 without side-lobes at a current of 6A.   Photonic micro and sub-micro structures in LiNbO3 crystals (EI CONFERENCE) 会议论文 ICO20: Materials and Nanostructures, August 21, 2005 - August 26, 2005, Changchun, China Wang P.; Bentini G. G.; Bianconi M.; Cerutti A.; Chiarini M.; Mazzoldi P.; Pennestri G.; Sada C.; She L. 收藏  |  浏览/下载：16/0  |  提交时间：2013/03/25 High energy lasers processing of materials is knowing an increasing interest since it not only can make manufacturing faster  cleaner  and more accurate but also because it opens up entirely new technologies and manufacturing methods  that are simply not available by using standard techniques. In this paper  an experimental set-up  based on pulsed KrF excimer Laser  assembled for surface patterning of mono and two-dimensional  (1D-2D)  micro and submicro structures on LiNbO3(LN) crystal  will be described in detail. The apparatus has been used to produce photonic structures in LN  both by patterning of PMMA photoresist  and by direct surface patterning through laser ablation or direct laser writing. The structures and properties of the photonic crystals fabricated by using this apparatus have been investigated  and the preliminary results will be presented.