Efficient 2.1 μm laser action of an Ho:ScYSiO₅ (Ho:SYSO) mixed crystal at room temperature

Abstract

We present a new 2.1 μm Ho:SYSO laser, resonantly pumped by a 1940.3 nm Tm-fiber laser. With an output transmittance of 11.4%, the Ho:SYSO laser produced a 2097.7 nm continuous wave with up to 4.1 W of output power and 53.4% of slope efficiency with respect to the absorbed pump power. The measured beam quality factor (M 2 ) of the Ho:SYSO laser was approximately 1.2 at the maximum output level.