Real-time spatial-spectral interference measurements of ultrashort optical pulses

Real-time linear spectral interference measurements of ultrashort pulses are shown experimentally. The technique involves measurements of the two-dimensional interference pattern of the spectral interference between a reference and a signal pulse propagating at an angle with respect to each other. No postprocessing is needed to extract the spectral phase difference between the two pulses. Quadratic spectral phase distortions as well as spectral phase discontinuities are measured. The method is applicable to single-shot measurements of ultraweak pulses and is useful for identification of the critical adjustments of ultrashort pulse shapers and compressors. (C) 1997 Optical Society of America.