Low-cost multimode diode-pumped Tm:YAG and Tm:LuAG lasers

Abstract

We report a continuous-wave operation of Tm:YAG and Tm:LuAG lasers pumped with a low-cost, multimodeAlGaAs laser diode. First, the lifetime and the absorbance behavior of 5 mm, 6% Tm3+ -doped YAG and LuAG crystalswere thoroughly investigated. A low-cost multimode 3W laser diode at 781 nm was then used as a pump source for theTm3+ -doped laser systems. Using three different output couplers, up to 636 mW of output power was obtained fromTm:YAG laser, with a slope efficiency of 29% at 2017 nm. The maximum output power was 637 mW in the Tm:LuAGlaser, with a slope efficiency of 28% at 2023 nm. The lasing performances showed a decreasing slope efficiency with anincreasing level of output coupling, which leads to a high upconversion. Furthermore, using a birefringent filter in theresonators, the laser outputs were tuned from 1942 to 2086 nm in the Tm:YAG resonator and from 1931 to 2107 nm inthe Tm:LuAG case.