利用近场多波长激光雷达对生物气溶胶的偏振测量

基于非球形粒子偏振特性，设计并试制了近场偏振激光雷达。该系统包含二个激光光源和退偏组件，激光束的线偏振度为1/500，偏振和弹性散射信号由孔径200 mm的卡塞格林望远镜接收。在一个半封闭的生物气溶胶腔里，对10种生物气溶胶，按355, 532, 1064 nm的顺次进行线偏振测量。数据分析结果表明，退偏比表现出较强的波长依赖性; 利用欧氏相关度和马哈拉诺比斯距离，可以确定多波长线偏数据的差异，并对生物气溶胶进行分辨。

Bioaerosols Polarization Measurement by Short-Range Multi-Wavelength Lidar

Based on polarization characteristics of non-spherical particles, a short range lidar system for real-time standoff detection of bioaerosols was developed. The system includes two laser sources and depolarization components. Linear polarization purity of the laser beam is 1/500, the polarization and elastic scattering signals are collected by a Cassegrainian telescope. In a semi-closed bioaerosol chamber, 10 kinds of bioaerosol were mixed and interrogated by 355, 532, 1064 nm laser beam sequently. Linear polarization measurements were performed. The results showed that the depolarization ratios are wavelength-dependent, and the identification of bioaerosols can be achieved through the application of Euclidian correlation degree and Mhalanobis distance.