高增益高提取效率的固体激光放大器研究

发布时间：2018-07-10 11:55

本文选题：激光放大器 + 增益　；参考：《长春理工大学》2017年硕士论文

【摘要】：一微米主振荡功率放大技术已广泛应用于工业加工等领域。Nd:YVO4晶体因优异的激光性能得到了广泛的应用。本文对基于Nd:YVO4晶体作为增益介质的高增益高提取效率1.06μm固体激光放大器展开研究。从激光放大理论出发,通过研究光信号在激光介质的放大过程,对不同情况下的光信号增益与提取效率进行分析,为激光器的设计提供理论依据。其次,通过建立直角坐标系下稳态热传导模型,分析晶体参数对晶体热分布的影响并得出相应晶体热焦距。依据热仿真结果,讨论谐振腔腔型以及各腔参数对腔内光束耦合的影响。在放大级的设计中,分析了放大过程中的增益变化与ABCD矩阵,设计了以热透镜效应实现的级间耦合与线偏振旋转方式,实现了Nd:YVO4晶体的共轴双程结构。在实验中,平凸腔结构的信号源在100kHz的调Q状态下,输出的平均功率为12W,脉冲宽度为25.5ns。在单程放大结构中,实验测量了不同光束耦合比、抽运功率对放大级输出特性的影响。基于上述实验结果,搭建双程放大结构,在平均功率为12W的脉冲信号注入下,获得输出功率为36.9W,对应光光转换效率为44.5%。相同条件下,注入13W的连续信号时,双程放大器获得的输出功率为38.9W,对应光光转化效率为45.2%。
[Abstract]:One-micron main oscillator power amplification technique has been widely used in industrial processing. ND: YVO4 crystal has been widely used because of its excellent laser performance. In this paper, the high gain and high extraction efficiency 1.06 渭 m solid-state laser amplifier based on ND: YVO4 crystal as gain medium is studied. Based on the theory of laser amplification, the gain and extraction efficiency of optical signal under different conditions are analyzed by studying the amplification process of optical signal in laser medium, which provides a theoretical basis for the design of laser. Secondly, the influence of crystal parameters on the thermal distribution of the crystal is analyzed by establishing the steady-state heat conduction model in the right-angle coordinate system, and the corresponding thermal focal length of the crystal is obtained. Based on the results of thermal simulation, the influence of cavity type and cavity parameters on the beam coupling in the cavity is discussed. In the design of amplifier stage, the gain variation and ABCD matrix during amplification are analyzed, and the coupling between stages and linear polarization rotation mode based on thermal lens effect is designed. The coaxial biaxial structure of ND: YVO4 crystal is realized. In the experiment, the average output power and pulse width of the signal source with flat convex cavity structure are 12W and 25.5ns at 100kHz Q-switched state. The effects of different beam coupling ratios and pump power on the output characteristics of the amplifier stage are experimentally measured. Based on the above experimental results, a double-pass amplifier structure is constructed, and the output power is 36.9 W, corresponding to the optical conversion efficiency of 44.5 W, under the pulse signal injection of 12 W. Under the same conditions, the output power of the double-pass amplifier is 38.9 W, corresponding to the optical conversion efficiency of 45.2 W, when the 13W continuous signal is injected.
【学位授予单位】：长春理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN24;TN722

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