相位恢复法是一种利用多个离焦面光强分布采用基于傅里叶变换的迭代变换恢复瞳面相位分布的波前传感方法。采用改进的傅里叶迭代变换算法, 当波前传感范围超过1个波长时, 需要在迭代过程中采用相位解包裹算法。针对18块正六边形拼接的复杂光瞳, 提出采用路径无关和最小二乘相结合的混合相位解包裹算法, 提高了波前传感精度和动态范围。通过仿真比较了所提方法与单独采用一种相位解包裹方法时的波前传感性能, 分析了所提方法的动态范围及噪声对算法精度的影响。仿真结果表明, 当波前PV值为3.5λ时, 算法的精度为λ/43; 当噪声RMS值为10(图像为12Bit量化)时, 算法的精度优于λ/40。

Phase retrieval is a wavefront sensing method that uses the iterative transformation based on Fourier transform to recover the pupil phase distribution by using the intensity distribution of multiple defocus planes. The method uses Modified Gerchberg-Saxton (G-S) iterative transform algorithm. When the wavefront aberration exceeds one wavelengths, the phase unwrapping algorithm is needed in the iterative process. To accomplish the phase retrieval of the mosaic pupil of 18 hexagonal segments, a hybrid phase unwrapping algorithm based on path independent and least-mean-square is proposed, and improved the wavefront sensing accuracy and dynamic range. The wavefront sensing performance of this method and single use of one phase unwrapping method are compared, the dynamic range and the influence of noise on the accuracy of the algorithm are studied in paper's proposed method. The simulation results show that when the PV value of the wavefront aberration is 3.5λ, the accuracy of the algorithm is λ/43; when the noise RMS value is 10 (the image is 12Bit quantized), the accuracy of the algorithm is better than λ/40.