雨滴对波长0.532μm激光光束的衰减特性

Attenuation of 0.532μm Laser Beam Through Raindrops

降雨对激光信号产生严重的衰减,从而给激光近炸引信的应用带来一定的影响。激光在雨中的传输衰减已在红外波段有了深入研究,而可见光波段激光在雨中传输的衰减特性还未见报道。在夫琅禾费衍射和几何光学散射理论基础上,建立单雨滴对波长0.532μm绿激光光束的传输衰减模型,通过实验测试多雨滴的透过率并与理论计算结果进行对比,误差不超过2%.研究分析表明:雨滴对波长0.532μm激光的吸收率为1.32×10-9,可忽略;在传播过程中,只考虑雨滴的散射衰减,并且受衍射与几何散射共同影响;而近红外激光由于雨滴的吸收作用使得透过率低于0.532μm.雨滴的衰减特性研究为绿激光在降雨环境下引信中的应用提供了一定的理论依据。

Rainfall can bring serious attenuation to the laser signals,so it has some influence on the laser proximity fuze applied in the rain.The attenuation of laser beam propagating in the rain has been researched in the infrared range,but the attenuation of visible light laser in the rain has not been reported.Therefore,based on the Fraunhofer diffraction and geometric optics theory,an attenuation model for 0.532μm laser beam propagating through the raindrops was established.Then the transmittance of several raindrops was theoretically calculated and validated by experiments,and the error was less than 2%.The investigations indicate that absorptivity of the raindrop for 0.532μm laser beam is 1.32×10-9 and can be ignored,so only the raindrop scattering is considered in the laser transmission and influenced by the diffraction and geometric scattering synchronously.The transmittance of near infrared laser is lower than that of 0.532μm laser due to the raindrop absorption.The attenuation model of 0.532μm laser provides a theoretical basis for the green laser applied in the proximity fuze operating in the rain.