Solution of the phase problem for time-dependent optical signals by an interference system

A new method is proposed for an analysis of amplitude–phase characteristics of short laser radiation pulses. The method is based on determination of a pattern of the interference between the spectra of the investigated pulse and of a second pulse obtained from the original one by a frequency shift. An analysis of the intensity distribution in the spectral interference pattern can yield the phases of the spectral components, which–in combination with the conventional spectrum–provides complete information on the time dependence of the signal.