Measurement of ultrashort pulse durations by interferometric autocorrelation: influence of various parameters.

The interferometric autocorrelation technique for the measurement of ultrashort pulse durations is studied in detail. Effects of group velocity mismatch, group velocity dispersion, fundamental depletion, and pulse shape are carefully examined. A simple semianalytical calculation is developed that takes group velocity mismatch into account that can be used to predict the validity of this technique with real experimental parameters. A more complete calculation is also presented to analyze the effects of fundamental depletion or phase mismatch. Finally, the influence of the pulse shape is considered and a simple experimental procedure is proposed to determine whether a pulse is transform limited.