Phase retrieval as a means of wavefront sensing

The paper discusses how phase retrieval can be employed as a robust technique for estimating the wavefront distortion using a lenslet array. It is shown that the principal problem of phase retrieval, namely divergence is considerably reduced when the aperture is subdivided. The results obtained compare favorably with the alternative approach of phase diversity. Furthermore, the introduction of prior information, in the form of statistical information of the distortion, is shown to considerably enhance the success of the phase retrieval.