Non-Invasive Optical Detection of Submicron Domains in Lithium Niobate Crystals

A non-invasive detection of shallow submicron-scale ferroelectric domains has been demonstrated by optical diffraction technique. Periodic sub-micron domains are of great interest to the field of optics and optoeletronics and non-destructive techniques for their accurate inspection are always desirable. Submicron-scale domains have been fabricated by electric field overpoling in lithium niobate substrates and successively inspected by visualizing the diffraction grating just after poling and destructive etching process. The results demonstrate the usefulness of the technique for a non-invasive and rapid inspection of submicron-scale domains otherwise not visible by the conventional non-destructive methods available nowadays.