title: 10 kHz 40 W Ti:sapphire regenerative ring amplifier.
abstract: A cryogenically cooled Ti:sapphire regenerative ring amplifier was developed as a laser for generating a laser-produced plasma light source. With a 10 kHz 180 W pump laser, the amplifier output is 40 W before compression and 26 W after compression. We believe it to be the current highest average-power output from a single stage Ti:sapphire amplifier. The effective focal length of the thermal lens is measured to be 2.2 m at 100 K for 180 W of pump power. With a 1 m focal length lens placed in the resonator, the effect of a thermal lens on the resonator mode is suppressed. High conversion efficiency is achieved for the whole pumping power range without any additional measures for thermal compensation.
authors.affiliation: Photonics Research Institute, National Institute of Advanced Industrial Science and Technology, Umezono, Tsukuba, Japan. i.matsushima@aist.go.jp
authors.forename: Isao
authors.initials: I
authors.lastname: Matsushima
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Yashiro
authors.forename: Toshihisa
authors.initials: T
authors.lastname: Tomie