Anisotropy of domain broadening in periodically poled lithium niobate crystals

We experimentally study the dependence of reversed domain broadening of lithium niobate (LiNbO3) wafers on their poling electrode configurations. Experiments show that the reversed domain area is anisotropic and has 60 degrees symmetry. The slightest domain broadening takes place as the poling stripe electrode parallels to the diagonals of hexagonal domain walls. We suppose the anisotropy of domain expansions is directly related to the symmetry of LiNbO3 crystal lattices, and it can be understood by considering the anisotropoic distributions of tangential component of electric field and the spontaneous polarization on domain walls. (c) 2006 American Institute of Physics.