Fabrication of 100-nm-period domain structure in lithium niobate on insulator
Jianan Ma, Cheng Xiaoyan, Ningchong Zheng, Pengcheng Chen, Xiaoyi Xu, Tianxin Wang, Dunzhao Wei, Yuefeng Nie, Shining Zhu, Min Xiao, Yong Zhang
Abstract
Lithium niobate on insulator (LNOI) is a powerful platform for integrated photonic circuits. Recently, advanced applications in nonlinear and quantum optics require to controllably fabricate nano-resolution domain structures in LNOI. Here, we report on the fabrication of stable domain structures with sub-100 nm feature size through piezoelectric force microscopy (PFM) tip poling in a z-cut LNOI. In experiment, the domain dot with an initial diameter of 80 nm and the domain line with an initial width of 50 nm can survive after a storage of more than 3 months. Particularly, we demonstrate the successful fabrication of 1D stable domain array with a period down to 100 nm and a duty cycle of ∼50%. Our method paves the way to precisely manipulate frequency conversion and quantum entanglement on an LNOI chip.