Intracavity sum-frequency generation of 3.23Â W continuous-wave yellow light in an Nd:YAG laser

By carefully designing a co-folding-arm plane-plane symmetrical L-shaped Nd:YAG laser cavity, both same waist width and same waist position of 1064 and 1319 nm beam are obtained in an intracavity type II KTP crystal. After optimizing the intracavity power ratio of two beams by choosing proper pump power of the two beams, continuous-wave yellow light at 589 nm is obtained with output power of 3.23 W. To the best of our knowledge, this is the highest output power at 589 nm by an intracavity sum-frequency Nd:YAG laser.