激光雷达探测污染气体最小浓度的估算方法

探测大气中污染气体的浓度是激光雷达的一个重要应用方面,最小可探测浓度是衡量一个雷达系统的重要指标。从测量的误差理论出发、分析得出了一般情况下．被测量最小值的估算方法：当被测量的相对误差为100％时,此时的被测量的大小就是可探测量的最小值。把此方法应用到激光雷达中来．得出了差分吸收激光雷达和拉曼雷达探测污染气体最小浓度估算公式．并把它们与已有的估算公式进行了比较,指出了原有估算公式的不足。     

Iteration method for the inversion of simulated multiwavelength lidar signals to determine aerosol size distribution

A new method is proposed to derive the size distribution of aerosol from the simulated multiwavelength lidar extinction coefficients. The basis for this iteration is to consider the extinction efficiency factor of particles as a set of weighting function covering the entire radius region of a distribution. The weighting functions are calculated exactly from Mie theory. This method extends the inversion region by subtracting some extinction coefficient. The radius range of simulated size distribution is 0.1－10.0μm, the inversion radius range is 0.1－2.0μm, but the inverted size distributions are in good agreement with the simulated one.     

Nd:YAG四倍频激光抽运甲烷后的受激拉曼效应及其物理机制分析

从理论上分析了激光被聚焦到高压气体内可能发生各种非线性现象的规律及其相互作用和相互干扰.在实验中把Nd:YAG四倍频激光聚焦到充有甲烷的拉曼管内,测各阶斯特克斯光输出能量与气压pa、透镜焦距f和输入能量Ep之间的关系.实验结果与理论分析定性地相符合，这就为我们优化和利用受激拉曼过程提供了理论和实验依据. 关键词： 非线性过程 受激拉曼散射 四波混频 激光诱导离解