为了分析激光合束光学系统的成像质量, 本文研究了激光合束光学系统的热耦合效应。借助光学设计软件建立激光合束系统模型, 基于传热学理论, 根据光学系统结构及流场条件参数建立气体流体模型。根据光线追迹法编写用户自定义函数, 通过数值模拟定量研究了介质气体热效应引起的波像差系数。仿真分析了气体热效应在不同时间下对激光合束光学系统的影响。结果表明, 受重力影响激光合束系统热效应的旋转对称性变得不再明显, 随着温度升高呈现分层变化, 且非均匀热效应以低阶像差为主。将波像差系数导入光学设计软件, 可实现复杂光场与热场耦合传函的定量分析, 波像差劣化03λ, 传递函数下降01。

The thermal coupling effecting on laser beam combining optical system is studied in this paper in order to analyze the imaging quality of the system. The laser beam combining system is modeled using optical design software, and the gas fluid model is established based on heat transfer theory according to the structure of the optical system and the parameters of the flow field. According to the ray tracing method, a user-defined function is defined and the wave aberration coefficient caused by the thermal effect of the medium gas is quantitatively studied through numerical simulation. The influence of gas thermal effect on the laser optical system at different time is simulated and analyzed. The results show that the rotational symmetry of the thermal effect in the beam combination system is no longer noticeable under the influence of gravity, but stratification changes with increasing temperature, and the non-uniform thermal effect is dominated by low-order aberrations. The wave aberration coefficient can be imported into the optical design software to quantitatively analyze the transfer function of the coupling of the complex optical field and the thermal field. At this time, the wave aberration is deteriorated by 03λ, and the transfer function value is decreased by 01.