Large-angle electro-optic laser scanner on LiTaO₃ fabricated by in situ monitoring of ferroelectric-domain micropatterning

We report on a horn-shaped electro-optic scanner based on a ferroelectric LiTaO₃ wafer that is capable of scanning 632.8-nm light by an unprecedented 14.88° angle for extraordinary polarized light and by 4.05° for ordinary polarized light. The device concept is based on micropatterning ferroelectric domains in the shape of a series of optimized prisms whose refractive index is electric field tunable through the electro-optic effect. We demonstrate what we believe is a novel technique of using electro-optic imaging microscopy for in situ monitoring of the process of domain micropatterning during device fabrication, thus eliminating imperfect process control based on ex situ monitoring of transient currents.