CHARACTERISTICS OF FEMTOSECOND PULSES NEAR 1.5-MU-M IN A SELF-MODE-LOCKED CR4+-YAG LASER

The operating characteristics of a self-mode-locked Cr4(+):YAG laser that produces sub-100-fs pulses are described. Stable, nearly transform-limited pulses are obtained at a central wavelength longer than 1.50 mu m, and the spectrum of the wavelength is extended past 1.60 mu m, over the net gain bandwidth of the laser material. The group-velocity dispersion and the third-order dispersion of the Cr-doped YAG rod are measured by a Fourier-transform interferometric cross-correlation technique, indicating that the group-velocity dispersion vanishes at a wavelength of 1.59 mu m.