Ce/sup 3+/:LiCaAlF/sub 6/ crystal for high-gain or high-peak-power amplification of ultraviolet femtosecond pulses and new potential ultraviolet gain medium: Ce/sup 3+/:LiSr/sub 0.8/Ca/sub 0.2/AlF/sub 6

• Published in: IEEE journal of selected topics in quantum electronics Vol. 7; no. 4; pp. 542 - 550
• Main Authors: Liu, Z., Kozeki, T., Suzuki, Y., Sarukura, N., Shimamura, K., Fukuda, T., Hirano, M., Hosono, H.
• Format: Journal Article
• Language: English
• Published: IEEE 01.07.2001
• Subjects: Chirp; Gain; Laser excitation; Optical pulses; Pulse amplifiers; Pulse compression methods; Pump lasers; Scalability; Space vector pulse width modulation; Tunable circuits and devices
• ISSN: 1077-260X; 1558-4542
• DOI: 10.1109/2944.974225

To develop high-peak-power ultrashort pulse laser systems in the ultraviolet region, a large Ce/sup 3+/:LiCaAlF/sub 6/ (Ce:LiCAF) crystal, a tunable ultraviolet laser medium with large saturation fluence and broad gain spectrum width, was grown successfully with a diameter of more than 70 mm. To demonstrate high small signal gain, a four-pass confocal amplifier with 60 dB gain and 54 /spl mu/J output energy was constructed. Chirped pulse amplification (CPA) in the ultraviolet region was demonstrated using Ce:LiCAF for higher energy extraction. A modified bow-tie-style four-pass amplifier pumped by 100-mJ 266-nm 10-Hz pulses from a Q-switched Nd:YAG laser had 370-times gain and delivered 6-mJ 290-nm pulses. After dispersion compensation, the output pulses can be compressed down to 115 fs. This is the first ultraviolet, all-solid-state high-peak-power CPA laser system using ultraviolet gain media, and this demonstration shows further scalability of the Ce:LiCAF CPA system. Additionally, a new gain medium, Ce/sup 3+/:LiSr/sub 0.8/Ca/sub 0.2/AlF/sub 6/, with longer fluorescence lifetime and sufficient gain spectrum width over 18 nm was grown to upgrade this system as a candidate for a final power amplifier gain module.