红外偏振成像系统的成像条件分析

摘要

As the infrared polarization system is very sensitive to the observation factors like observing-angle,light waveband,light intensity,target material and the atmospheric transmittance,it is necessary to study on those factors to make sure the infrared-polarization system working in a good status.First,the polarization state of the target was de-scribed by Fresnel Reflection and Kerchief’s law;then,an experimental system for infrared-polarization imaging was set up with an infrared polariscope which was made of BaF2 (waveband 2~30μm);third,several contradistinctive ex-periments had been done with different imaging factors such as different observing-angles,light waveband,light inten-sity and different target’s properties to analyze the results and get the conclusions.The experiments show the similar results compared to theoretical analysis and simulation:the contrast of the target and the background is enhanced in all those experiments;as the angle of incidence get close to the Brewster’s angle,the degree of polarization get bigger,but the Brewster’s angle may not be the best observing angle for infrared polarization imaging system,and this is an inno-vation of the research;stronger light intensity and the glazed surface of the target also make the degree of polarization bigger.The conclusions may be helpful to target-searching and polarization imaging.%红外偏振成像技术是未来目标搜索方法的研究热点，它对于入射角、目标表面粗糙度等条件比较敏感，为使红外偏振成像系统有效工作，有必要研究系统成像条件。研究从菲涅尔反射定理和基尔霍夫定律出发，分析了偏振产生原理；针对不同入射角、入射光强、观测波段、目标表面粗糙度、目标材质等观测因素对成像效果的影响，通过定性定量分析、数据仿真、对比实验得出结论。实验结果与之前的理论分析吻合，即当入射角越接近布儒斯特角时，反射光的线偏振程度越大，发现布儒斯特角并非红外偏振成像的最佳观测角；当光照强度越大，目标表面越光滑时，偏振度也越大。对于将偏振成像技术在目标搜索、跟瞄等领域的工程化应用有着重要的意义。