High-beam-quality 2 μm tunable Tm:GdScO₃ laser pumped by a 793 nm laser diode

Abstract

The continuous wave laser characteristics of a Tm:GdScO3 laser were researched in this work. Under the absorbed pump power of 19.11 W, a maximum output power of 4.41 W was obtained at 1978 nm, corresponding to the slope efficiency of 28.25%. With a quartz birefringent filter (BF), a broad wavelength tunable range from 1845 nm to 2006 nm was obtained, for the first time. Then, a long-pass filter was used to replace the quartz BF. A maximum output power of 3.21 W was obtained at 2002 nm, with the slope efficiency of 21.98%. The beam quality factors M 2 for horizontal and vertical directions were 1.14 and 1.11, respectively.