Abstract

The development of the new solid-state laser material, Cr:LiSAF,¹ offers an important alternative for short-pulse laser applications. Like Ti:sapphire, LiSAF exhibits a broad gain bandwidth, tunable from 760 to 950 nm. Unlike Ti:sapphire, it has a long upper state lifetime (67 µsec). The combination of this long upper state lifetime with a significant overlap of the material's absorption bands with the emission spectrum of xenon flashlamps make Cr:LiSAF attractive for flashlamp pumping. This advantage, coupled with die fact that LiSAF has a low nonlinear refractive index and low thermal lensing, make it a good candidate for highpower, femtosecond laser systems. Using the technique of chirped pulse amplification' we have developed a one hundred femtosecond laser system capable of producing peak power near two terawatts. We have developed a Cr:LiSAF regenerative amplifier that produces a pulse energy above 10 mJ at a repetition, rate of 5 Hz.³ These pulses are then further amplified at 1 Hz yielding 500 mJ. Recompression produces a 250-mJ pulse with a near transform limited pulse width of 135 fsec.

© 1993 Optical Society of America