All-solid-state, ultraviolet, high power laser system using Ce:LiCAF as a gain medium

Authors

Shingo Ono Institute for Molecular Science, Okazaki City, Japan
Nobuhiko Sarukura Institute for Molecular Science, Okazaki City, Japan
Hiroki Sato Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Japan
Akira Yoshikawa Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Japan
Tsuguo Fukuda Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Japan

Abstract

High-peak-power, femtosecond, ultraviolet (UV) lasers have recently attracted a large amount of interest for material processing applications in addition to the traditional scientific applications. Chirped pulse amplification (CPA) in the UV region has been demonstrated for the first time, using a broad-band Ce³⁺:LiCaAlF₆ (Ce:LiCAF) crystal as the gain medium. The peak power of the amplified and compressed pulse (τ ~ 115 fs) at 290 nm reached to 30 GW. For further peak-power scaling up to terawatt (TW) level, one can try to compress the pulse width and improve the output pulse energy.
Since the Ce:LiCAF crystal has a broad tunability from 281 nm to 315 nm, it shows the possibility of the generation and amplification of 3 fs pulse. Such ultraviolet pulse is required as the seed pulse of TW-class Ce:LiCAF laser system. The duration of the seed pulse provided by frequency tripling of the output from the Ti:sapphire regenerative amplifier was measured to be 210 fs. The seed pulses were focused into the hollow fiber filled with Ar gas. After the hollow fiber, the spectral bandwidth of the pulses is broadened due to self-phase-modulation (SPM). The pulse was compressed down to 25 fs duration by the dispersion-compensating using a Brewster quartz prism pair.
The fourth harmonics of Nd:YAG lasers is an ideal pumping source because of the absorption spectra of Ce:LiCAF crystal. We have succeeded to generate the total forth harmonics output energy (266 nm) of 430 mJ with the total conversion efficiency of 30.5%, using three Li₂B₄O₇ (LB₄) crystals. By such performance of pump source, we designed a coaxially-pumped large-aperture Ce:LiCAF double-pass power-amplifier module. The output energy reached to 98 mJ for 13 mJ seed pulse with the extraction efficiency of 25%.
These elements will be the key devices for TW-class UV CPA laser systems.

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Issue

2004: Proceedings of the 22nd Samahang Pisika ng Pilipinas Physics Congress

Article ID

SPP-2004-INV-PS-09

Section

Plenary Sessions

Published

2004-10-25

How to Cite

[1]

S Ono, N Sarukura, H Sato, A Yoshikawa, and T Fukuda, All-solid-state, ultraviolet, high power laser system using Ce:LiCAF as a gain medium, Proceedings of the Samahang Pisika ng Pilipinas 22, SPP-2004-INV-PS-09 (2004). URL: https://proceedings.spp-online.org/article/view/SPP-2004-INV-PS-09.