Pulsed lasers with high average output power in the green spectral range are of interest for laser annealing applications. In this paper an efficient pulsed diode-pumped Yb:YAG thin disk laser with intracavity frequency doubling is presented. The Yb:YAG laser crystal disk has a thickness of 180 &mgr;m and a diameter of 10 mm and is pumped by a laser diode stack at a wavelength of 938 nm. The disk is soldered to a water-cooled Cu-W heat sink and exhibits a nearly perfect spherical surface. The folded resonator is dynamically stable with a beam factor of M² = 5 and which is matched to the requirements of the application. Acousto-optical and electro-optical switches are investigated to operate the laser in the cavity-dumping mode. An average output power of 150 W at 515 nm is achieved. The diode-to-green efficiency is about 28%. A critically phase matched LBO crystal is used for intracavity second harmonic generation. We show that stable pulsing is obtained from 10 kHz to 150 kHz. The pulse-width can be varied from 200 ns to 700 ns by control of the low-loss period of the switching element. The experimental results are compared with theoretical modeling of the system and first application results are discussed.

Date Published: 19 February 2007
PDF: 7 pages
Proc. SPIE 6451, Solid State Lasers XVI: Technology and Devices, 64510D (19 February 2007); doi: 10.1117/12.709548

Published in SPIE Proceedings Vol. 6451:
Solid State Lasers XVI: Technology and Devices
Hanna J. Hoffman; Ramesh K. Shori; Norman Hodgson, Editor(s)