Investigation on reversed domain structures in lithium niobate crystals patterned by interference lithography

We demonstrate fabrication of periodically poled lithium niobate samples by electric field poling, after patterning by interference lithography. Furthermore we investigate the poling process at an overpoling regime which caused the appearance of submicron dot domains very similar to those induced by backswitch but different in nature. We show the possibility for realizing submicron-scaled threedimensional domain patterns that could be applied to the construction of photonic crystals and in nonlinear optics. We show that high etch-rate applied to such structures allows to obtain pyramidal-like submicron relief structures which in principle could find application for waveguide construction in photonic bandgap devices.