High-Power Continuous Wave Green Generation by Single-Pass Frequency Doubling of a Nd:GdVO₄Laser in a Periodically Poled MgO:LiNbO₃Operating at Room Temperature

Abstract

Continuous-wave power of 0.89 W at 531 nm with 14.3% conversion efficiency is reported at room temperature from a 2-mm-thick periodically polled uncoated MgO:LiNbO3 by single-pass frequency doubling of a diode end-pumped Nd:GdVO4 laser; the corresponding internal green power and conversion efficiency were 1.03 W and 16.5%, respectively. The MgO:LiNbO3 device of 6.95-µm domain period was fabricated by using a high-voltage multi-pulse poling method; uniform periodicity and 50% duty cycle were obtained on the entire 10-mm-long crystal. The sample exhibited an effective nonlinear coefficient of 14 pm/V (∼88% of the ideal nonlinear coefficient), resulting in a measured normalized conversion efficiency of 2.7%/W. To the authors best knowledge this is the highest power ever obtained by quasi-phase matching process at room temperature.