Thin disk Tm-laser based on highly doped Tm:KLu(WO4)2/KLu(WO4)2 epitaxy

• Published in: Laser physics letters 2010-06, Vol.7 (6), p.435-439
• Main Authors: Vatnik, S., Vedin, I., Pujol, M.C., Mateos, X., Carvajal, J.J., Aguilo, M., Díaz, F., Griebner, U., Petrov, V.
• Format: Article
• Language: English
• Subjects: epitaxial layers; monoclinic double tungstates; thin-disk lasers; Tm-lasers
• ISSN: 1612-2011; 1612-202X
• DOI: 10.1002/lapl.201010010

: Continuous‐wave (CW) Tm‐laser operation is achieved for the first time using the thin disk laser concept and an epitaxial active element based on the monoclinic KLu(WO4)2 crystal with 15 at.% thulium doping of the overgrown layer, which is only 80 μm thick. A single double pass of the pump radiation from the diode‐laser ensures efficient pumping due to the large absorption of the active layer. For output coupling between 0.4% and 2.8%, the slope efficiency in the CW regime is in the 7–11% range and the laser threshold amounts to 1.5–2.5 W of absorbed pump power. The laser emission spectra are centered at ∼ 1850, 1915, and 1940 nm for output couplers of 2.8%, 1.6%, and 0.4% transmission, respectively. In all cases the emission spectra are “structured”, con‐sisting of a number (typically 5–10) of narrow emission lines spread irregularly over 15–30 nm. (© 2010 by Astro Ltd., Published exclusively by WILEY‐VCH Verlag GmbH & Co. KGaA)