90-fs tunable optical pulses obtained by two-stage pulse compression

We report a factor of 65 compression of the 5.9-ps [full width at half-maximum (FWHM)] pulses from a mode-locked dye laser by a two-stage technique. In each stage the laser pulses were frequency broadened and linearly chirped by passage through a single-mode optical fiber, and then compressed by traversal of a diffraction grating based dispersive delay line. The final compressed output pulses had pulse widths of 90 fs (FWHM), peak powers of more than five times that of the input pulses, and were continuously tunable over the 300-Å range of the laser dye.