双板条激光介质热效应研究
文献类型:学位论文
作者 | 黄燕 |
学位类别 | 硕士 |
答辩日期 | 2005 |
授予单位 | 中国科学院上海光学精密机械研究所 |
导师 | 胡企铨 |
关键词 | 双板条侧面泵浦 增益分布 热效应 瞬态温度分布 |
其他题名 | The analysis of the thermal effects of Double-slab Nd: YAG laser medium |
中文摘要 | 近年来,全固态的大功率半导体抽运固体激光器的研究取得了长足的发展,更由于具有高效率、寿命长、使用与维护方便、体积小等优点,高功率固体激光器已经广泛应用于工业加工、材料处理、军事等多方面领域,但是固体激光器的功率提高受到很多限制,尤其是如何克服热效应(包括热透镜效应、热致退偏效应等)的影响,是人们一直不断研究的重点。本文在综述板条激光器发展过程的基础上,提出了一种新型的双板条结构Nd:YAG激光器,它采用面抽运的双板条工作介质,并对板条两侧面以不同温度的冷却液冷却。据此工作方式,利用一套反射镜组,使从第一块介质板条高温一侧出射的激光束对称地进入另一块板条的低温一侧,从而对由于温度分布不均造成的波面畸变可实现自校正,消除一阶热效应。在此种板条结构模型下,分析了板条激光器板条介质的特性及抽运源的特点。同时,还对激光工作物质内增益分布特性、温度分布特性、热应力进行理论研究和计算机的模拟;对介质的吸收系数进行了讨论,表明在研制高重复频率的激光器不宜使用高掺杂浓度的增益介质。在实验研究方面,据此抽运结构制作了一套双板条串联Nd:YAG激光器,并相应的搭建了一套Mach-Zehnder干涉仪系统,对双板条激光器的热畸变进行了测量和分析。从而,进一步证实此种抽运结构的增益介质板条有可能研制成高重复率、高平均功率、高光束质量KW级的Nd:YAG激光振荡器或放大器。 |
英文摘要 | Diode-pumped solid-state lasers (DPSSL) have the advantages of high efficiency, long lifetime, high reliability and easy use, compact structure. In the last decade a lot of progresses have been made. This results in the increasing use of DPSSL in various applications such as industry, material process, military and so on. However, thermally induced distortions (including thermal lens effects, stress induced biaxial focusing, and stress induced birefringence.) in laser crystals limit the scaling of high power output at high beam quality. The thermal effects are a focus of attention in the studying of high power laser. A novel scheme of double-slab Nd:YAG laser is proposed, which utilize the face-pumped slab medium cooled by liquid with different temperatures in both sides. According to the method of operation, a set of reflectors can reverse the laser beams, which symmetrically travel along the higher temperature side of the former mediate slab through the lower temperature side of the later one. The distortion of wavefront caused by the non-uniform temperature distribution of the laser gain media slab will be self-corrected in this structure. The optical path eliminated first-order thermal and stress induced focus. The characteristic of the slab medium and pumped sources are analysed in this running mode. Meantime, supposed models of the slab medium's temperature distribution and stress state are presented. The analytic solutions for the models are derived out. Then absorption coefficient is also discussed. The result indicates that the doped concentration cannot be so high for designing high repetition frequency laser. The experimental setup and the double Nd:YAG slab will be presented and discussed. Correspondingly, the interferometer of the Mach-Zehnder is set up, which is measured the thermal distortion of the slab laser in this structure, Thereby, it proves that high repetition frequency, high average power at kW level and high beam quality Nd: YAG slab laser or amplifier with this pumping structure can be developed. |
语种 | 中文 |
源URL | [http://ir.siom.ac.cn/handle/181231/16495] ![]() |
专题 | 上海光学精密机械研究所_学位论文 |
推荐引用方式 GB/T 7714 | 黄燕. 双板条激光介质热效应研究[D]. 中国科学院上海光学精密机械研究所. 2005. |
入库方式: OAI收割
来源:上海光学精密机械研究所
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