Chirped-pulse amplification in Ti:sapphire beyond 1 /spl mu/m

Chirped-pulse amplification in Ti:sapphire in the low-gain region above /spl 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/sub 00/ Ti:sapphire regenerative amplifier exhibiting a net gain of 10/sup 9/ (from 10 pJ to 9 mJ) at 1053 nm with extremely stable energy output (/spl plusmn/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.<
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