基于小物镜系统的热像差影响因素分析

Analysis of Influence Factors of Thermal Aberrations Based on the Small Lens System

光机热集成分析是光机结构设计中的重要环节,对光学系统像质的预测与补偿有着重要的参考价值。针对小物镜系统,进行光机热集成分析,结果表明该系统产生的热像差较大,影响系统光学性能,其中温度升高导致折射率变化引入的系统热像差较大;结构热变形引入的系统热像差较小,可以忽略;镜片与支撑结构之间的导热、上下窗口的空气扰动、机械结构外表面的环境对流也会存在一定影响,但影响较小。由此可知系统热像差的主要影响因素是热载的大小,设计过程中减少透镜厚度及材料吸收率,降低系统热载,是减小光学系统热像差最为有效的途径。

Thermal structural optical integrated analysis is an effective way to estimate optical image quality during optical and mechanical design stage. Thermal structural optical integrated analysis of a small lens system is conducted. The results indicate that thermal aberrations of the system are higher, affecting optical properties of the system. Contribution to the thermal aberrations induced by change of refractive index is larger than that by surface deformation. Thermal conductance between the lens and the support structures, air turbulence in the upper and lower windows, and environmental convection of the outer surface of the mechanical structure influence the thermal aberrations finitely, and the primary influence factor is thermal load. Reducing thickness of the lens and absorption rate of materials will decrease thermal load and thermal aberrations of the system decreased effectively.