Fringe field-tunable LC refractive index interface for in-plane beam steering applications

We report on the electrically tunable optical structure based on dual-domain nematic liquid crystal (LC) alignment for in-plane beam steering applications. The device operates due to the total internal reflection of an extraordinary beam at the LC refractive index interface that separates homeotropic and planar-aligned nematics. Patterned electrodes were used in order to switch on the refractive index interface in the bulk of a planar-aligned LC layer. An outstanding feature of the proposed device is the function of tuning the spatial position of the LC interface by means of a fringing electric field, which allowed one to implement wide range light beam microscanning, as well as to realize in-plane angular beam steering with a milliradian resolution.