LD side-pumped Nd∶YAG/S-KTP intracavity frequency doubled high power CW red laser at 660nm

LD side-pumped Nd∶YAG/S-KTP intracavity frequency-doubled high power CW red laser at 660nm is reported. LD pumping module is composed of nine 20W laser diodes, which has maximum pump power of 180W. The resonant cavity parameters are optimized so as to generate fundamental oscillation at 1319nm when the 3mm×65mm Nd∶YAG rod is pumped continuously. With a KTP crystal (type Ⅱ critical phasematching), 6.8W of CW red laser output and the optical-optical conversion efficiency of 4.3% are obtained when pumping current is 22A.