In this letter, a new recursive algorithm to implement phase retrieval
from two intensities in the two-dimensional Fourier transform domain
is presented. In terms of the cascading property and additivity of the
order of the fractional Fourier transform, a set of convolution equat
ions is exactly derived. Applying recursive algorithm, these equations
can be easily solved. This approach simplifies significantly computat
ional manipulations comparing with conventional iterative algorithms a
nd does not need initial phase distribution.