共查询到20条相似文献,搜索用时 109 毫秒
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报道了不同热边界和泵浦结构下激光晶体的热效应情况。理论上,基于星载激光器的工作特点,通过建立符合激光晶体工作状态的热模型,模拟了Nd:YAG晶体受到具有高斯分布半导体激光侧面泵浦时的温度场分布,分析了热边界、泵浦方式以及泵浦光斑、吸收系数等泵浦参数对温度场的影响。将激光晶体热透镜作薄透镜近似,进行了热透镜焦距理论计算和实验测量。五面环形泵浦结构,泵浦功率4 500 W,10 Hz重复频率下,Nd:YAG晶体的热透镜焦距约9.5 m,实验结果与理论仿真结果基本符合。文中建立的模型与实验方法为预测激光晶体的热效应提供了一种有效工具,为激光器设计提供依据。 相似文献
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二极管阵列侧面泵浦固体激光介质的光场分布 总被引:8,自引:0,他引:8
研究LD阵列侧面泵浦Nd:YAG激光器泵浦光场的分布特点。首先,在已建立的二极管单bar单侧面泵浦YAG晶体泵浦光场分布数值模型的基础上,进一步建立了适用于激光二极管阵列多侧面泵浦YAG晶体的泵浦光场分布数值模型。然后,根据所建模型,采用光线追迹的方法,借助Matlab编程模拟了单侧面、二侧面、三侧面、五侧面泵浦方式的泵浦光分布特点.分析了系统参数:介质半径、介质吸收系数、光束光腰半径、泵浦距离、二极管bar间距、介质表面粗糙程度对泵浦光分布特性的影响,总结出了一般规律。可为二极管泵浦固体激光器的结构设计和实验研究提供理论参考。在理论分析的基础上,进行了单侧面、二侧面泵浦方式的二极管阵列直接侧面泵浦固体激光器的实验研究。实验结果与理论分析结果基本相符,验证了所建数值模型的正确性。该数值模型的特点是:采用光线追迹方法;适用于漫反射表面工作物质:适用于多种侧面直接泵浦方式,具有可扩充性。 相似文献
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高功率激光二极管端面抽运复合晶体激光器的研究 总被引:8,自引:5,他引:8
在高功率激光二极管抽运固体激光器中,热效应已成为获得高输出功率和高光束质量的最大阻碍因素.用有限元方法研究了高功率激光二极管端面抽运Nd∶YVO4激光器中热透镜分布规律,提出了用复合晶体消除热透镜效应的方法.研究表明在端面抽运的传统单一Nd∶YVO4晶体激光器中,由于抽运功率密度很高,热透镜效应非常严重,由端面变形而造成的热透镜效应约占整个热透镜效应的50%;而采用复合晶体能够很好地消除由端面变形而造成的热透镜效应,同时得到很好的冷却效果,获得比采用传统单一晶体高出许多的基模输出功率和更好的光束质量.实验证明,采用复合结构晶体在23 W的抽运功率水平下得到了11 W的基模输出功率,光束质量因子M2 <1 5,光光转换效率达到48%. 相似文献
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HU Shao-yun ZHONG Ming ZUO Yan FAN Hong-ying 《光电子快报》2006,2(4):278-281
Beamfocusing and higher-order wavefront distortiondue to heat dissipationinalaser gain mediumarei mpor-tant considerationsinthe design of solid-statelasers be-cause wavefront distortion can profoundly influence theperformance of a givenlaser design.Althou… 相似文献
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HU Shao-yun ZHONG Ming ZUO Yan FAN Hong-ying 《光电子快报》2006,2(4):278-281
Beamfocusing and higher-order wavefront distortiondue to heat dissipationinalaser gain mediumarei mpor-tant considerationsinthe design of solid-statelasers be-cause wavefront distortion can profoundly influence theperformance of a givenlaser design.Althou… 相似文献
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Xiong Z. Li Z.G. Moore N. Huang W.L. Lim G.C. 《Quantum Electronics, IEEE Journal of》2003,39(8):979-986
An investigation of thermal lensing effects in longitudinally diode-pumped Nd:YVO/sub 4/ lasers is made in detail both numerically and experimentally. A finite-element model is used to theoretically simulate thermal lensing in various Nd:YVO/sub 4/ crystals and pumping scenarios. The predicted values for thermally induced lens strengths are compared with experimentally observed results. We find that these two sets of results are in broad agreement, provided that the spatial profile of the pump-induced heat generation is accurately modeled. The saturation of the pump absorption is found to be of particular importance in producing an accurate prediction of the thermal lens strength, and a composite structure of the crystals is desirable to relieve the thermal lensing. 相似文献
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Thermal lensing in diode-pumped ytterbium Lasers-Part I: theoretical analysis and wavefront measurements 总被引:1,自引:0,他引:1
Chenais S. Balembois F. Druon F. Lucas-Leclin G. Georges P. 《Quantum Electronics, IEEE Journal of》2004,40(9):1217-1234
A theoretical and experimental study of thermal lensing in Yb-doped crystals is presented. In this first part, we focus on theoretical considerations and we describe an original technique suitable for thermal lensing measurements in end-pumped materials. We first derive an expression of the temperature distribution with account of absorption saturation and pump beam divergence inside the crystal, and we address a more general discussion on the particularities of quasi-three-level lasers, as far as thermal effects and fracture issues are concerned. The thermal lens was then measured using a simple technique based on a Shack-Hartmann wavefront analyzer, under lasing and nonlasing conditions. We demonstrate that the technique allows precise wavefront measurements even on small spots. Thermal lensing measurements are finally presented in Yb-doped YAG, GGG, YCOB, GdCOB, KGW, and YSO crystals. 相似文献
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Reduction of CO2 -laser-induced thermal lensing in liquid CS2 by the application of a dc electric field is reported. The electric field is found to destroy the effect of natural convection on the thermal lens and induce convection patterns dependent upon field orientation that enhance heat transfer and reduce the negative lensing effect. The experimental results are found to be consistent with calculations of electric forces present in fluids with a radially decreasing electrical conductivity. 相似文献
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Barnes N.P. Thomas M.E. Koch G.J. Marsh W.B. 《Quantum Electronics, IEEE Journal of》1995,31(5):962-969
Atmospheric absorption degrades laser performance both by absorbing laser energy within the laser resonator, which increases the loss, and by inducing a thermal lens in the atmosphere. Atmospheric thermal lensing can be quite severe, even when the absorption coefficient is quite modest. A model is developed which describes atmospheric thermal lensing; time constants, which are associated with the establishment and decay of the atmospheric thermal lens, are determined; experiments are performed using an injection seeded Ti:Al 2O3 laser tuned to the H2O absorption lines near 0.815 μm to validate the model; dependence of the atmospheric thermal lens on the laser energy and absorption coefficient were measured and found to agree with the model. In addition, the decay of the atmospheric thermal lens with time was measured and also found to agree with the model predictions 相似文献