1 W 589 nm Coherent Light-Source Achieved by Quasi-Intracavity Sum-Frequency Generation

We proposed a novel configuration for efficient generation of coherent 589-nm light by sum-frequency generation mixing 1064 and 1319 nm emitted from two continuous-wave Nd:YAG lasers. A 5-mm-long periodically-poled KTiOPO4 was used as a nonlinear optical crystal and it was set in the 1064-nm-Nd:YAG laser. Output beam oscillated from the 1319-nm-Nd:YAG laser was superimposed on a propergation axis of 1064-nm beam stored in the 1064-nm laser using a beam combiner from outside of the laser.?Output power of sum frequency reached to 1 W and it was ten times higher than that by extracavity sum-frequency generation using the same appatatus.