CHIRPED-PULSE AMPLIFICATION IN TI-SAPPHIRE BEYOND 1-MU-M

Chirped-pulse amplification in Ti:sapphire in the low-gain region above 1 mu m is described, Direct measurement of the stimulated emission cross section shows that the value is nearly 50% lower in this region than previously reported based on extrapolation from fluorescence data at shorter wavelengths, We have developed a TEM(00) Ti:sapphire regenerative amplifier exhibiting a net gain of 10(9) (from 10 pJ to 9 mJ) at: 1053 nm with extremely stable energy output (+/-3%), Further amplification in a ring amplifier produces in excess of 60 mJ at a 10 Hz repetition rate, The performance of these amplifiers is compared with a theoretical model which includes whole-beam self-focusing, mode-size variation due to a radial gain profile, and spectra-temporal saturation.