MEASURING ULTRASHORT LASER-PULSES IN THE TIME-FREQUENCY DOMAIN USING FREQUENCY-RESOLVED OPTICAL GATING

We summarize the problem of measuring an ultrashort laser pulse and de scribe in detail a technique that completely characterizes a pulse in time: frequency-resolved optical gating. Emphasis is placed on the cho ice of experimental beam geometry and the implementation of the iterat ive phase-retrieval algorithm that together yield an accurate measurem ent of the pulse time-dependent intensity and phase over a wide range of circumstances. We compare several commonly used beam geometries, di splaying sample traces for each and showing where each is appropriate, and we give a detailed description of the pulse-retrieval algorithm f or each of these cases. (C) 1997 American Institute of Physics.