Tunable two-dimensional hexagonal phase array in domain-engineered z-cut lithium niobate crystal

Abstract

An optical phase array with tunable phase step is demonstrated. The phase array consists of a 2-dimensional hexagonal lattice of inverted ferroelectric domains fabricated on a z-cut lithium niobate substrate. The electro-optically tunable phase step is obtained by the application of an external electric field along the z axis of the crystal via transparent electrodes. Theoretical analysis and experimental results are presented showing that a tunable and flexible adaptive optical illuminator device can be realized by combining the electro-optic tunability with the Talbot effect. Generation of a multiplicity of light pattern is shown