基于衍射光栅曲率波前传感器的实时波前重构研究

Real-time wavefront reconstruction based on diffraction grating wavefront curvature sensor

自适应光学系统要求波前传感器能实现动态实时测量,曲率波前传感技术符合这一发展要求。一种新型的基于扭曲衍射光栅的曲率波前传感器在探测装置的实现方法方面具有较大优势,其波前重构已应用于光学度量。根据衍射光学理论,对其探测信号进行数值模拟,并利用Neumann边界条件的Green函数法对其波前重构进行数值模拟。结果表明:Green函数法归结为2矩阵相乘,计算速度快,达到实时重构要求;Green函数法对阶数不高的Zernike多项式重构效果较好;影响重构误差的主要因素是光强梯度的边界噪声。

Adaptive optical systems require the wavefront sensors to realize real-time dynamic measurement, and the wavefront curvature sensing technology can meet such requirement. A novel wavefront curvature sensor based on the twisted diffraction grating has a greater advantage in the realization of detecting device, and its wavefront reconstruction algorithm is used for the measurement of optical surfaces. The numerical simulation of the detection signal was implemented with the theory of diffraction optics, and the numerical simulation of the wavefront reconstruction was realized with Green function algorithm under Neumann boundary conditions. The results indicate that the speed of Green function algorithm is fast, it meets the requirement of the real-time wavefront reconstruction, and the result of wavefront reconstruction for low-order Zernike polynomials is good. The analysis shows that the major source of wavefront reconstruction error is the boundary noise in the gradient of light intensity.