Optimization of LiNbO_3 photonic crystals: toward 3D LiNbO_3 micro-components

Abstract

We report easy-to-implement techniques to improve the reflectivity of LiNbO₃ photonic crystals within the photonic bandgap. Firstly, we show that widening the channel waveguides confines the optical modes in the vertical direction, which leads to the development of the first 2D-PhCs on Ti-indiffused LiNbO₃ waveguides. We also report the first optical characterization of PhCs implemented on ridge LiNbO₃ waveguides. The reflectivity is measured using a swept-source optical coherence tomography (OCT) system, together with the transmission spectrum. Finally we report 3D-PhCs LiNbO₃ fabricated by Focused Ion Beam milling on the side of ridge waveguides.