红外系统后向反射光的光强研究

摘要

According to the theory of diffraction, the intensity distribution of laser reflected from infrared system is analyzed. The diffraction pattern of spot center intensity in different transmission distance is studied and the relationship between spot intensity and radius is established. The reflection region can be divided into the transmission area, Fresnel diffraction area and Fraunhofer diffraction area. In Fresnel diffraction area, the intensity of spot center change light to dark, the intensity of spot center change violent vibration from 0～1 km, and reach peak value between 1～3 km, then reduce gradually with the reflection distance increasing. In Fraunhofer diffraction area, the spot center is light spot, around encircle light and dark ring．%根据衍射光学理论分析了红外系统后向反射光强的分布。在菲涅耳衍射区域内，反射光斑中心光强是呈明暗变化的，反射光斑中心光强在0～1km内剧烈振荡，在1～3km之间达到峰值，然后随传输距离的继续增加反射光斑中心光强逐渐减小；在夫琅和费衍射区域内，光斑图像中央是亮光斑，周围环绕着明暗交替的圆环。