Two-dimensional characterization of relief microstructures in lithium niobate through digital holographic microscopy

We report on the application of digital holographic microscopy for the investigation and the micro-topography reconstruction of different microstructures realized in bulk lithium niobate by differential etching of reversed ferroelectric domain patterns. These structures have a range of applications in optical ridge waveguides, alignment structures, V-grooves, micro-tips and micro-cantilever beams. Precise control of the surface quality and topography is required. The technique allows us to digitally obtain a high-fidelity surface topography description of the specimen with only one image acquisition, allowing relatively simple and compact set-ups able to give quantitative information on the objects´ morphology. The advantages of this technique, compared to traditional microscopy, are discussed.