Stabilization of High-Power Intracavity-Frequency-Doubled Solid-State Laser by Advanced Resonator Design in Consideration of Thermal Lensing of Nonlinear Crystal

Abstract

We have compensated for thermal lensing of nonlinear crystal and Nd: YAG rods by advanced resonator designin a high-power diode-side-pumped intracavity-frequency-doubled CW Nd: YAG laser. The maximum greenoutput power of 27.0 W was generated with the beam quality of M²=7.9. This value is, to our knowledge, thehighest green output power in CW diode-pumped solid-state lasers. It was found that the green powerfluctuation is caused by the unstable zone of the resonator due to the thermal lensing of the nonlinear crystal (KTP). TEM₀₀-mode green output power of 16.3 W was also generated.