Nondestructive remote imaging of ferroelectric domain distributions with high three-dimensional resolution

The domain distribution in the bulk and at the surface of ferroelectric crystals is imaged by second-harmonic microscopy with three-dimensional far-field optical resolution. The nondestructive technique allows us to investigate the success of a poling procedure in a fabrication state of an integrated optical device in which the poling electrodes have not been removed. Additionally, a confocal linear optical imaging technique is introduced, which reveals the surface topography with ±0.7 nm height sensitivity. At the surface of a periodically poled specimen, we detect unexpected and unwanted surface topographies that correspond to the domain structure. The search for improved fabrication parameters that guarantee smooth surfaces could be substantially promoted with our topography-detection technique.