ALEXANDRITE-PUMPED ALEXANDRITE REGENERATIVE AMPLIFIER FOR FEMTOSECONDPULSE AMPLIFICATION

We demonstrate a regenerative amplifier incorporating alexandrite as t he gain medium that is pumped by an alexandrite laser. Temperature-alt ered gain permitted the 728-nm alexandrite pump laser, operating at ro om temperature, to pump a 780-800-nm alexandrite laser that was mainta ined at elevated temperatures. 200-fs pulses from a Ti:sapphire oscill ator were amplified to the millijoule level. This system also amplifie d femtosecond pulses from a frequency-doubled Er-doped fiber laser. (C ) 1996 Optical Society of America