Abstract

High-peak-power, femtosecond, ultraviolet (UV) laser system has become extremely attractive for material processing applications' additional to the traditional scientific applications.² There have been three approaches for UV high-peak power lasers. One is the nonlinear frequency conversion of the Ti:sapphire amplifier system.^3,4 The other approach is KrF excimer amplifiers.^5,6 The final approach is the chirped pulse amplification (CPA) laser system using UV gain medium. Ce³⁺:LiCaAlF₆ (Ce:LiCAF) is the tunable solid- state UV laser medium with sufficient bandwidth and high saturation fluence.^7,8 The fourth harmonics of Nd:YAG lasers is idea pumping source.^7,8 UV pumping is not drawback owing to the recent development of new nonlinear crystals like CsLiB₆O₁₀⁹ and Li₂B₄O₇.¹⁰ Previously, we had reported the first UV CPA using rather small Ce:LiCAF crystal up to 30-GW level.¹¹ The main problems for TW UV all-solid-state lasers are the scalable power-amplifier-module design that is capable to handle high pulse energy in UV region. In this paper, we will report a coaxially-pumped large-aperture power-amplifier module. Moreover, the detailed design parameters for further energy scaling are successfully evaluated.

© 2002 Optical Society of America