基于Mueller矩阵分析测量的激光纳米增益介质在线诊断方法研究

以掺杂稀土离子的气相纳米粒子为增益介质的纳米气体激光器，在实现高能激光输出的同时，结构紧凑，运行高效，散热良好。通过火焰燃烧的方式合成稀土掺杂YAG纳米粒子具有天然优势，是纳米气相增益介质的有效合成方式，但目前亟需解决的是粒子尺寸、形貌、体积浓度等多参数的在线诊断。本项目拟基于Mueller矩阵测量分析实现燃烧合成YAG纳米粒子的在线诊断方法。首先计算不同尺寸、晶相、体积密度的纳米粒子的Mueller矩阵，分析矩阵的各元素以及由矩阵得到的退偏振指数、偏振度等参数，探究这些参数反应粒子特性的可能性；之后，搭建亚微秒Mueller矩阵测量系统，针对标准粒子，实验验证上述参数的有效性；最后，优化设计，校正误差，将Muller矩阵测量系统应用于燃烧合成YAG纳米粒子的在线诊断。该项目为YAG粒子的调控燃烧合成及纳米气体激光器的发展提供技术支撑，同时为其他纳米粒子的燃烧合成在线诊断提供重要参考

The high-energy laser output can be achieved by using gas phase nanoparticles doped with rare earth ions as gain medium, which has compact structure, high efficiency and good heat dissipation. The synthesis of rare earth doped YAG nanoparticles by flame combustion is an effective method for the synthesis of nano-gas phase gain media, but the on-line diagnosis of particle size, morphology and distribution is urgently needed. This project is based on Mueller matrix measurement and analysis to realize the on-line diagnosis of combustion synthesis of YAG nanoparticles. The Mueller matrix of nanoparticles of different size, crystal phase and volume density, the elements of the matrix, the depolarization index and the degree of polarization obtained from the matrix are calculated to explore the possibility of these parameters reflecting the particle characteristics. Then, a sub-microsecond Mueller matrix measurement system is constructed, and the effectiveness of the above parameters is verified by experiments for standard particles. Finally, the Muller matrix measurement system is applied to the on-line diagnosis of combustion synthetic YAG nanoparticles by optimizing design and correcting error. This project provides technical support for YAG particle combustion synthesis and the development of nanoparticle gas laser, and provides important reference for on-line combustion synthesis diagnosis of other nanoparticles.