TEMPORAL INTERFEROMETRIC MEASUREMENT OF FEMTOSECOND SPECTRAL PHASE

Fourier spectral analysis of temporal interference resulting from beat s between a reference optical frequency and a number of spectral compo nents of a femtosecond optical pulse yields the spectral phase directl y without the need for iterative calculations. A periodic multiple-sli t mask placed in the Fourier plane of a femtosecond pulse shaper selec ts an ensemble of frequency components for measurement by cross correl ation. An additional, out-of-period slit selects the reference frequen cy so that none of the desired beat tones overlaps redundant tones. We measure positive and negative cubic phase distortion introduced when the pulse shaper lens is tilted and the phase discontinuity of a 0-pi pulse (odd pulse) with a 13-slit mask. Finally, we demonstrate measure ment of the spectral phase associated with true time delays with 17 sl its. (C) 1996 Optical Society of America