Ce3+:LiCaAlF6 crystal for high-gain orhigh-peak-power amplification of ultraviolet femtosecond pulses and newpotential ultraviolet gain medium: Ce3+:LiSr0.8Ca0.2AlF6

摘要

To develop high-peak-power ultrashort pulse laser systems in thenultraviolet region, a large Ce3+:LiCaAlF6n(Ce:LiCAF) crystal, a tunable ultraviolet laser medium with largensaturation fluence and broad gain spectrum width, was grown successfullynwith a diameter of more than 70 mm. To demonstrate high small signalngain, a four-pass confocal amplifier with 60 dB gain and 54 ΜJ outputnenergy was constructed. Chirped pulse amplification (CPA) in thenultraviolet region was demonstrated using Ce:LiCAF for higher energynextraction. A modified bow-tie-style four-pass amplifier pumped byn100-mJ 266-nm 10-Hz pulses from a Q-switched Nd:YAG laser had 370-timesngain and delivered 6-mJ 290-nm pulses. After dispersion compensation,nthe output pulses can be compressed down to 115 fs. This is the firstnultraviolet, all-solid-state high-peak-power CPA laser system usingnultraviolet gain media, and this demonstration shows further scalabilitynof the Ce:LiCAF CPA system. Additionally, a new gain medium, Ce3+n:LiSr0.8Ca0.2AlF6, with longernfluorescence lifetime and sufficient gain spectrum width over 18 nm wasngrown to upgrade this system as a candidate for a final power amplifierngain module