We first discuss the discrete fractional Fourier transform and present
some essential properties. We then propose a recursive algorithm to i
mplement phase retrieval from two intensities in the fractional Fourie
r transform domain. This approach can significantly simplify computati
onal manipulations and does not need an initial phase estimate compare
d with conventional iterative algorithms. Simulation results show that
this approach can successfully recover the phase from two intensities
. (C) 1998 Optical Society of America.