Ultraviolet femtosecond pulse amplification using Ce/sup 3+/:LiCaAlF/sub 6/ crystal as gain medium

Summary form only given. There have been continuous efforts for obtaining high-peak-power, femtosecond, ultraviolet pulses. The solid-state ultraviolet laser medium Ce/sup 3+/:LiCaAlF/sub 6/ (Ce:LiCAF) was shown to have broad tunability from 281 nm to 315 nm corresponding to the bandwidth of a 3-fs pulse. Additionally, it has a high saturation fluence of 115 mJ/cm/sup 2/. For the future terawatt Ce:LiCAF chirped pulse amplification (CPA) laser system, we have successfully grown a 5-cm diameter Ce:LiCAF crystal. In this presentation, we report high-gain confocal four-pass amplification and chirped pulse amplification in the ultraviolet region using Ce:LiCAF The CPA amplifier has 370-times gain and delivers 6-mJ, 290-nm pulses.