Performance evaluation of phase diversity wave-front sensing in obtaining high-resolution images

Phase diversity wave-front sensing technique (PD) is a widely known estimation method of wave-front deformation of optical imaging system. Base on PD, high-resolution image could be obtained by eliminating the influence of wave-front deformation through online or offline restoration. However, there are a variety of errors that could affect the accuracy and efficiency in obtaining wave-front estimation and in reconstructing images. Hence in this paper, a large number of simulations are carried out to evaluate the performance of PD considering five major factors including the value of introduced defocus, the defocus error, the noise level, the scale of wave-front aberration, and the size of the images. Two criteria are adopted to do the evaluation. One is based on consistency between the estimated wave-front and the purposely introduced one. The other is based on the accuracy of reconstructed images. The results demonstrate that the introduced defocus value should be controlled in the range of 0.2 λ -1.2 λ , Gaussian noise level should be less than 0.0005, wave-front aberration should be in the range of 0.3 λ -1.2 λ , and defocus error should be controlled in the range of -50μm -10μm (corresponding to -0.0988 λ to -0.0198 λ ). Besides those, as long as the size of the restored image is less than 128*128 pixels, the total estimation and reconstruction time will not exceed 5.96s.