Fabrication of lithium niobate metasurfaces via a combination of FIB and ICP-RIE
Chunyan Jin, Wei Wu, Lei Cao, Bofeng Gao, Jiaxin Chen, Wei Cai, Mengxin Ren, Jingjun Xu
Abstract
Lithium niobate (LN) metasurfaces have emerged as a new platform for manipulating electromagnetic waves. Here, we report a fabrication technique for LN nano-grating metasurfaces by combining focused ion beam (FIB) milling with inductively coupled plasma reactive ion etching (ICP-RIE). Steep sidewalls with angles larger than 80° are achieved. Sharp quasi-bound states in the continuum are observed from our metasurfaces. The measured transmission spectra show good agreement with the numerical simulations, confirming the high quality of the fabricated metasurfaces. Our technique can be applied to fabricate the LN metasurfaces with sharp resonances for various applications in optical communications, on-chip photonics, laser physics, sensing, and so on.