Efficient diode-pumped continuous-wave monolithic 1.9μm micro-laser based on Tm3+:BaGd2(MoO4)4 cleaved plate

Abstract Efficient monolithic 1.9 μm micro-laser was realized in a 1.1-mm-thick, 6.4 at.% Tm3+:BaGd2(MoO4)4 unprocessed cleaved plate coated with the cavity mirrors directly. End-pumped by a fiber-coupled 795 nm diode laser, continuous-wave output power of 250 mW was obtained when incident pump power was 1.15 W. Slope efficiencies with respect to incident and absorbed pump power were 36% and 61%, respectively. End-pumped by a single-stripe 805 nm diode laser, which is more favorable for constructing a compact and inexpensive 1.9 μm all-solid-state laser, continuous-wave output power of 100 mW was obtained when incident pump power was 2.0 W. Slope efficiencies with respect to incident and absorbed pump power were 11% and 23%, respectively. The spectra and spatial profiles of the monolithic Tm3+:BGM micro-laser were also measured and analyzed.