Pulse compression with supercontinuum generation in microstructure fibers

We demonstrate the generation of 5.5-fs pulses by dispersive compression of a supercontinuum generated with 15-fs pulses from a Ti:sapphire laser in a 5-mm-long microstructure fiber. The generated continuum is characterized with a setup for cross-correlation spectral-phase interferometry for direct electric-field reconstruction (SPIDER). The reconstructed spectral phase is used as on input for an iterative algorithm optimizing the compressor phase profile. We also discuss the limitations of this technique concerning the achievable pulse duration, including aspects like limited spectral coherence of the supercontinuum, limited compressor resolution, and a limitation of the SPIDER technique. The coherence is limited by power fluctuations and the instability of the seed laser. (C) 2005 Optical Society of America.