Microstructuring of lithium niobate using differential etch-rate between inverted and non-inverted ferroelectric domains

Description/Abstract

Single crystal samples of lithium niobate have been spatially patterned with photoresist, and subsequently domain inverted using electric field poling, to produce a range of two dimensional spatial domain structures. Differential etching has subsequently been carried out using mixtures of hydrofluoric and nitric acids, at a range of temperatures between room temperature and the boiling point. The structures produced show very smooth, well defined, deep features, which have a range of applications in optical ridge waveguides, alignment structures, V-grooves, and micro-tips. Details are given of the fabrication procedures, and examples of structures are shown.