Highly efficient continuous-wave and passively Q-switched Yb:YLuGdCOB compact lasers

Highly efficient operation of an Yb:YLuGdCOB compact laser was demonstrated, producing an output power of 14.30 W around 1054 nm, with an optical-to-optical efficiency of 70.0% and a slope efficiency of 81%. In dual-polarization oscillation in an emission range of 1080 − 1085 nm, 11.37 W of output power was generated with a slope efficiency of 76%. Efficient passively Q-switched operation was also realized by incorporating a 2D MoTe 2 saturable absorber into the compact resonator, producing a maximum pulsed output power of 1.56 W at 1030 nm at a repetition rate of 481 kHz; while the largest attainable pulse energy, minimum pulse duration, and highest peak power were, respectively, 3.87 μJ, 26.2 ns, and 147.7 W. The pulse width proves to be the shortest, while the peak power is the highest ever reported for solid-state lasers passively Q-switched with 2D saturable absorbers.