光学系统折射率温度效应的模拟计算

提出一种计算折射率温度效应的新方案。该方案通过拟合有限元热分析得到离散节点温度，在透镜中建立连续的温度场。在计算CODE V光线追迹时，自编子程序根据追迹点的温度和输入数据，实时计算并返回相对折射率及其梯度信息，使折射率温度效应导致的光程变化的计算更为准确。在计算时可以把波长、大气压、折射率温度系数等作为自定义参量，输入到子程序中，使相对折射率的计算更为灵活。最后对一个红外光学系统进行了计算误差分析，得到了像质的变化情况，验证了该方案的可行性。

Simulated calculation for effect of temperature on refractive index in optical system

A new method to calculate the effect of temperature on refractive index is presented.A continuous temperature field was created in lens by fitting discrete node temperatures obtained from the finite element thermal analysis. Based on the temperature and input data of ray tracing points,the relative refractive index and its gradient information were calculated and returned to CODE V by the self-made subroutine in ray tracing process,which made the simulation more accurate. Parameters such as wavelength,atmospheric pressure,temperature coefficient of the refractive index were inputted as variables to make the calculation of the relative refractive index more flexible. At last,the analysis of the calculation error was performed,and feasibility of the way was confirmed.