Diode Pumped Solid-state Laser Used for Ocean Ladar

该论文主要研究了海洋测深雷达用全固化激光器.激光器在测深海洋激光雷达系统中是一个关键装置,系统所能探测的水内深度直接取决于激光脉冲的峰值功率.同时,激光脉冲的宽度、重复频率、脉冲输出功率的稳定性以及输出的光束质量对整个系统的工作性能都有影响.我们的目的就是综合考虑测深海洋激光雷达系统中对激光器件的各项具体要求,设计研制实用化的小型全固化激光器.我们采用凹-凸介稳结构谐振腔,LDA侧面直接泵浦Nd:YAG介质,KD*P晶体加压式电光调Q,KTP晶体腔外倍频,研制成功了适合于机载海洋测深的小型全固化激光器.这个激光器已经被正式用于国家军工项目的机载海洋测深系统.该论文的主要创新点为:1.计算机数值模拟了侧面直接泵浦结构激光介质中泵浦光场的分布情况,分析了泵浦参数对激光器性能的影响.由此得出了结论:通过优化设计,选取适当的泵浦参数,采用侧面直接泵浦的结构也能获得较高的泵浦光耦合效率和较好的光束质量.2.通过优化设计,研制成功了LDA侧面直接泵浦的全固化激光器,结构简单而稳定可靠,被成功地应用于军用的机载海洋测深系统.In this thesis, we mainly studied all-solid state laser used in ocean depth sounding ladar system. In the system, laser is a key device. The depth system can detect is depended on the peak power of laser pulse. And the performance of the whole system is also affected by laser's other parameters such as pulse width, frequence, et. So, our object is to research a practical compact all-solid state laser to achieve the require of the ocean ladar system. We design a Nd:YAG laser with a concave- convex cavity side direct pumping by LDA, Q-switched, frequency doubling with KTP out of cavity. The laser is very compact and all-solid state, it has been formally used in an airborne ocean depth sounding system of a national army item. It needn't use complex beam-shaping system in direct side-pumping by LDA. But in this case we care more about the pumping efficiency and laser quality. So we studied it by analog calculation. In the model of laser diode side-pumping method, we discussed how the parameters (absorption coefficient and distance between the laser diode and the medium) affect the homogeneity. The result of analog calculation shows that high pumping efficiency can also be getting in direct side-pumping method by optimizing the pumping parameter. It also been proved by experiment. There are two primary innovations in this thesis: 1. We made a calculating model of laser diode side-pumping method. And discussed how the parameters affect the homogeneity. After that, we get the conclusion that high pumping efficiency can also be getting in direct side-pumping method. 2. Based on the optimized design, we made an all-solid state laser with direct side pumping by LDA. The device is very compact and stable. It has been successfully used in an airborne ocean depth sounding system by army