Optical parametric oscillator on 1-mm-thick periodically poled LiNbO3 with 29 mm interaction length

A 1-mm-thick periodically poled LiNbO3 (PPLN) crystal with a domain-inverted period of 29.8 mu m and an interaction length of 29 mm has been successfully fabricated by an electric field poling process. The average ratio of the domain-inverted width to the domain-inverted period (duty cycle) on a +Z surface and a -Z surface were 54.01% and 57.10%, respectively. To investigate the uniformity of domain-inverted structures in the Y-Z plane, the distribution of the optical parametric oscillator (OPO) idler output energy was measured, and an almost constant OPO idler output energy was obtained at all positions on the Y-Z plane. Therefore, the 1-mm-thick periodically domain-inverted structure can be uniformly obtained over the entire aperture. Finally, the OPO using this PPLN crystal with a large aperture of 1 mm x 1 mm was demonstrated.