Optical surface test using phase retrieval method

Aiming at the problems of initial phase estimate, transmission factor and convergence judgment, a phase retrieval experiment based on iterative method was done by using a cylindrical lens as the testing object. The experiment results showed that inputting an appropriate initial estimate phase was important to accelerate the convergence rate of algorithm, avoid the local convergence and insure the validity of results. In order to eliminate the error caused by the instability of laser and the uniformity of detector, transmission factor which was calculated by performing the operation of division between the two measured planes- intensities was used in the spectrum propagation formula.