透射式红外光学系统的太阳杂散辐射分析

Solar stray radiation analysis of transmissive infrared optical system

杂散辐射可以定义为经过非正常成像光路进入到接收器中的能量。杂散辐射会降低光学系统的图像对比度和信噪比,严重时杂散辐射的能量会直接将目标能量湮没,严重影响红外光学系统正常工作。本文分析了透射式红外光学系统的杂散辐射特性,设计了物镜筒的消光螺纹和表面处理方式等抑制措施。通过点源透过率曲线分析了抑制措施的作用,并分析了消光螺纹自身辐射对光学系统的影响。最终通过对比成像实验验证,结果表明,消光螺纹对轴外的杂散辐射有明显的抑制作用;同时消光螺纹的自身辐射能量不会引入新的干扰源。

Stray radiation can be defined as the energy entering the detector through an abnormal imaging path,which will reduce the image contrast and signal-to-noise ratio of the optical system.In severe cases,the energy of stray radiation will directly annihilate the target energy,seriously affecting the normal operation of the infrared optical system.In this paper,the stray radiation characteristics of the transmissive infrared optical system are analyzed,and the suppression measures such as the extinction thread and surface treatment of the objective lens barrel are designed.The effect of suppression measures is analyzed by point source transmittance curve,and the effect of self-emitted radiation of extinction thread is analyzed.Finally,it is verified by contrast imaging experiment,and the results show that the extinction thread has an obvious inhibition effect on the off-axis stray radiation.At the same time,the self-emitted radiation energy of the extinction thread don′t introduce new interference source.