Mid-infrared dual-wavelength operation of a diode-pumped Tm:YScO3 laser

A simultaneous continuous-wave (CW) dual-wavelength Tm:YScO3 laser using a single birefringent filter (BF) was experimentally demonstrated. We calculated the wavelength-dependent loss property of the BF. By adjusting the BF plate, the spectral intensity ratio of the generated wavelengths can be maintained to be 1:1. A simultaneous CW dual-wavelength Tm:YScO3 laser at 1948 and 2098 nm is experimentally realized. For a pump power of 15.2 W, mid-infrared dual-wavelength laser radiation at 1948 and 2098 nm and 5.9 W of output power using a 5% output coupler could be generated. A slope efficiency of 42.2% with respect to the absorbed pump power and optical-to-optical efficiency of 38.8% for the highest-incident pump power were obtained. To our knowledge, this is the first study that has realized the dual-wavelength in a Tm:YScO3 laser.