Optical phase recovery in the dispersive Fourier transform

The dispersive Fourier transform permits real-time acquisition of optical spectra with analog-to-digital converters. The method utilizies the property that a signal's temporal envelope matches its spectral profile if sufficiently dispersed. Unfortunately, the dispersion demand can be substantial and signal losses in highly dispersive elements represent a significant challenge, especially outside the telecommunications band. We address this problem by experimentally demonstrating that a time-domain equivalent of the Gerchberg-Saxton algorithm removes the fundamental dispersion requirement in the dispersive Fourier transform. The algorithm recovers the phase from time-domain intensity measurements. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3271678]