光学传递函数是评价像质的重要指标, 是光学系统设计的重要辅助参数.基于背景纹影技术获取光线通过折射率场的位移场数据, 结合马吕斯定理, 获取了对应的波前梯度数据.结合光学传递函数计算方法, 实现对光学传递函数的获取.利用上述思路完成了对某平凸透镜光学传递函数的测量, 并将其与ZEMAX计算得到的光学传递函数进行比较.对比了低频处的实验结果和理论结果, 其误差不超过4.0%.分析了误差产生原因并验证了基于背景纹影技术对低通系统进行光学传递函数测量的可行性和有效性.

The optical transfer function is accepted as an essential index to evaluate the imaging quality and is an important auxiliary parameter for designing the optical system. Based on the background oriented schlieren, the displacement field data of the light passing through the refractive index field are obtained, and the corresponding wavefront gradient data is obtained by combining the Marius theorem. Combined with the geometric optical transfer function formula, the optical transfer function can be achieved. The optical transfer function of a flat convex lens is measured by the above idea and is compared with the optical transfer function results calculated by ZEMAX. Comparison of the experimental results and theoretical results at low frequencies is conducted and the error is less than 4%. Feasibility and validity of background oriented schlieren for measuring the optical transfer function of low-pass systems are verified.