Choice of phase filter in designing continuous phase plate with GS algorithm

The spectrum characteristics of initial phase and unwrapped phase have been analyzed respectively. The differences between the spectrum characteristics show that some high frequency modulation would be led into the unwrapped phase in the iterative process. According to the analysis and comparison, the cut-off frequency of phase filter should be equal to the cut-off frequency of initial phase in frequency-domain. Using this method, a continuous phase plate has been simulated, and the mean square error, energy utilization rate and top non-uniformity which corresponded to the far field spot are 0.267 2, 96.32% and 0.101 2.