14-FS PULSE GENERATION IN KERR-LENS MODE-LOCKED PRISMLESS CR-LISGAF AND CR-LISAF LASERS - OBSERVATION OF PULSE SELF-FREQUENCY SHIFT

Kerr-lens mode-locked Kr-laser-pumped Cr:LiSGaF and Cr:LiSAF lasers co ntaining only two newly developed low-loss chirped mirrors instead of conventional dielectric resonator mirrors and generating pulses of wid ths as small as 14-fs with as much as 100 mW of average output power a re reported. We report what is to our knowledge the first experimental observation of a pulse self-frequency shift in crystalline active med ia that are characteristic of such short pulses at megawatt intracavit y peak powers. We also believe this phenomenon to be one of the signif icant limiting factors for pulse duration in femtosecond Cr:LiSAF-type lasers. (C) 1997 Optical Society of America.