0.1μm 激光尘埃粒子计数器中点光源大立体角反射成像弥散斑及其处理

Reflexive Speckle Image of the Point Light Source in the Laser Airborne Particle Counter for 0.1μm and Its Processing

本文详细分析了一股凹面镜对点光源大立体角反射成像弥散斑二维分布的计算方法，进而设计了我国首台０．１μｍ激光尘埃粒子计数器光学传感器的矩形光敏区共轭成像空间滤波器。应用该滤波器后光学传感器的信噪比得到了显著提高。

The large solid angle reflexive condenser, which will bring serious distribution due to its non linearity, is uesd to collect the scattering light from the single particle in the optical sensor of the airborne particle counter. In this paper, therefore, the calculation methed of the two dimensional distribution of the reflexive speckle image of the point light source via the concave mirror is suggested in detail, and the spatial filter for conjugate image of rectangular sensitive volume in the optical sensor of the airborne particle counter for 0.1μm, the first in China, is designed. The theoretical analysis and experiments all show the prominent improvements of the signal tonoise ratio when this filter is added.