温度梯度对红外光学系统成像质量的影响

摘要

利用有限元分析方法对温度梯度环境下的红外光学系统进行仿真分析，并对系统的成像质量进行了评价。利用 ANSYS 软件建立了某红外光学系统的有限元模型，分析了红外透镜在温度梯度作用下的镜面面形变化；用 Zernike 多项式拟合变化后的镜面面形数据，并将Zernike 系数代入光学设计软件 ZEMAX 中，分析变形后光学系统的成像质量。结果表明，轴向温度梯度和径向温度梯度均会使光学元件的面形发生变化，使光学系统产生像差，导致系统的成像质量下降。在温度梯度相同时，径向温度梯度对成像质量的影响比轴向温度梯度更严重。%The simulation of temperature gradient about the infrared optical system was accomplished by finite element analysis,and the imaging quality of system was evaluated.The finite element model of the infrared optical system was established by ANSYS.The deformation of infrared lens’mirror surface under different temperature gradients was ana-lyzed.The Zernike polynomial was used to fit the data of mirror surface after deformation,and the Zernike coefficients were exported to the optical design software ZEMAX for analyzing the image quality of optical system.The results show that the mirror surface of optical element is changed by the temperature gradient,and the aberration of optical system is produced,so the image quality of optical system is decreased.At the same temperature gradient,the effect of the ra-dial temperature gradient on imaging quality is more serious than the axial temperature gradient.