Single-frequency laser at 473Â nm by use of twisted-mode technique

We experimentally demonstrate an all solid-state laser producing single-frequency output at 473 nm. Spatial gain hole-burning in the gain material has been eliminated by use of twisted-mode cavity approach. By carefully designing, a Z-cavity with two beam waists is chosen to provide the optimum beam radius in the gain medium Nd:YAG and second harmonic generation crystal LBO. A total output power of 85 mW was achieved, when the laser was diode-end-pumped at an incident power of 3.5 W, the light-light conversion efficiency is up to 2.4%.