Periodically poled lithium niobate on insulator (LNOI) ridge waveguides are desirable for high-efficiency nonlinear frequency conversions, and the fabrication process of such waveguides is crucial for device performance. In this work, we report fabrication and characterization of locally periodically poled ridge waveguides. Ridge waveguides were fabricated by dry etching, and then the high-voltage pulses were applied to locally poled ridge waveguides. Second harmonic generation with normalized conversion efficiency of 435.5% W-1·cm-2 was obtained in the periodically poled LNOI ridge waveguide, which was consistent with the triangular domain structure revealed by confocal microscopy.
Biao Mu, Xianfang Wu, Yunfei Niu, Yan Chen, Xinlun Cai, Yanxiao Gong, Zhenda Xie, Xiaopeng Hu, Shining Zhu. Locally periodically poled LNOI ridge waveguide for second harmonic generation [Invited][J]. Chinese Optics Letters, 2021, 19(6): 060007
