In-band pumping of high-power Ho:YAG lasers by laser diodes at 1.9μm

Abstract

We present for the first time a high-power Ho:YAG laser in-band pumped by a (AlGaIn)(AsSb) laser diode stack with 1910 nm centre wavelength. Using a single 60 mm long Ho:YAG rod in a simple and compact plane-plane resonator geometry a maximum laser output power of 40 W and a slope efficiency of 57% with respect to the absorbed pump power were obtained. A beam quality of M <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> < 4 was found.