Red and green dual-wavelength Pr:LiGdF4 laser with a single birefringent filter

Abstract

Abstract A simultaneous continuous-wave (CW) dual-wavelength Pr:LiGdF4 laser using a single birefringent filter (BF) plate under excitation with a frequency doubled optically pumped semiconductor laser (2 ω-OPSL) was experimentally demonstrated. We calculate 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 Pr:LiGdF4 laser at 604 and 523 nm is experimentally realized. For a pump power of 7.2 W, red and green dual-wavelength laser radiation at 604 and 523 nm and 1.25 W of output power using a 4% output coupler could be generated. A slope efficiency of 19.8% with respect to the absorbed pump power and optical-to-optical efficiency of 17.4% for the highest-incident pump power were obtained. To our knowledge, this is the first study that has realized a dual-wavelength in Pr:LiGdF4 laser.