PROCEEDINGS ARTICLE | February 17, 2017
Proc. SPIE. 10082, Solid State Lasers XXVI: Technology and Devices
KEYWORDS: Continuous wave operation, Graphene, Output couplers, Q switching, Spectroscopy, Crystals, Ions, Q switches, Semiconductor lasers, Laser spectroscopy, Thulium, Laser crystals, Q switched lasers, Single walled carbon nanotubes, Absorption, Carbon nanotubes
Absorption, stimulated-emission and gain cross-sections are determined for 3 at.% Tm:CaGdAlO<sub>4</sub>. This crystal is employed in a microchip laser diode-pumped at 802 nm. In the continuous-wave (CW) regime, this laser generates 1.16 W at 1883-1893 nm with a slope efficiency of 32% with respect to the absorbed pump power. Using a special "bandpass" output coupler, vibronic CW laser operation up to 2043 nm is achieved. For passive Q-switching of the Tm:CaGdAlO<sub>4</sub> laser-saturable absorbers (SAs) based on CVD-grown graphene and randomly-oriented arc-discharge single-walled carbon nanotubes (SWCNTs) in a PMMA film. The SWCNT-SA demonstrates superior performance. The laser produced a maximum average output power of 245 mW at 1844 nm with a slope efficiency of 8%. The latter corresponds to a pulse energy and duration of 6 μJ and 138 ns, respectively, at a repetition rate of 41 kHz. Using the graphene-SA, 2.8 μJ, 490 ns pulses are obtained at a repetition rate of 86 kHz.
