, and Bum Ku Rhee

We verified through a noncritical phase-matched second-harmonic generation experiment that the periodically-poled LiNbO 3 (PPLN) had a large effective nonlinear optical coefficient, demonstrating that the QPM grating was uniform throughout the entire length of PPLN. The quasi-phase matching temperature was 193.4 o C. The maximum SHG output power at the fundamen-tal power of 2.0 W was found to be 18.0 mW; generated second-harmonic beam was found to have no photorefractive effect