Probe of symmetry reduction at domain walls by nonlinear Cherenkov measurement

Bang Liu; Yuanlin Zheng; Xiaohui Zhao; Haigang Liu; Xianfeng Chen

doi:10.1364/OE.24.029459

Probe of symmetry reduction at domain walls by nonlinear Cherenkov measurement

Opt Express. 2016 Dec 26;24(26):29459-29464. doi: 10.1364/OE.24.029459.

Authors

Bang Liu, Yuanlin Zheng, Xiaohui Zhao, Haigang Liu, Xianfeng Chen

PMID: 28059332
DOI: 10.1364/OE.24.029459

Abstract

We report on the investigation of symmetrical properties of lithium niobate (LiNbO₃) domain walls utilizing the nonlinear Cherenkov radiation. Compared with LiNbO₃ bulk crystals, new nonzero elements of the χ⁽²⁾ tensor at domain walls are found by the Cherenkov second harmonic generation (CSHG) and Cherenkov sum frequency generation (CSFG) measurement. Experimentally, we demonstrate the symmetry reduction of domain walls, where the mirror inversion symmetry of LiNbO₃ lattice is broken while the threefold rotational symmetry still remains.