High-power simultaneous dual-wavelength emission of an end-pumped Nd:YAG laser using the quasi-three-level and the four-level transition

An efficient continuous-wave (CW) simultaneous dual-wavelength lasing (SDWL) of an LD end-pumped Nd:YAG laser utilizing a quasi-three-level transition at 946 nm and a four-level transition at 1064 nm is reported. A theoretical model has been introduced to determine the threshold conditions for SDWL. The temperature distributions of a Nd:YAG crystal under different pump powers have been analyzed. In the experiments, a CW SDWL output power of 5.12 W at a temperature of 273 K has been achieved with a pump power of 17 W, giving a slope efficiency of 16.36%.