Electro-optic beam deflector device
A substantially planar waveguide for dynamically controlling the out-of-plane angle at which a light beam exits the waveguide. Generally, liquid crystal materials may be disposed within a waveguide in a cladding proximate or adjacent to a core layer of the waveguide. In one example, the waveguide may contain one or more taper regions such that the light beam exits the waveguide and propagates out-of-the-plane of the waveguide into an out-coupling medium at a propagation angle. In one example, the waveguide may contain one or more electrodes onto which one or more voltages may be applied. The magnitude of the propagation angle may be electronically controlled by altered by controlling or altering the magnitude of the one or more applied voltages.
1. A waveguide for controllably steering a light beam, wherein the waveguide is characterized by an effective index of refraction, the waveguide comprising:
a substantially planar core through which the light beam propagates;
at least one top-cladding having a liquid crystal material therein, the at least one top cladding adjacent to the substantially planar core;
at least one bottom-cladding adjacent the substantially planar core such that the substantially planar core is between the at least one top-cladding and the at least one bottom-cladding, the at least one bottom-cladding having no liquid crystal material;
at least one optically transparent substrate to structurally support the core and the at least one top-cladding, the at least one optically transparent substrate providing an out-coupling medium to receive light from the substantially planar core;
at least one out-coupling medium positioned with the at least one bottom-cladding between the substrate and the core, the at least one out-coupling medium having an index of refraction that is larger than the effective index of refraction of the waveguide, wherein the out-coupling medium is separated from the core within the waveguide by the bottom cladding, wherein a thickness of the bottom cladding decreases from a first thickness near the input end of the waveguide to a second thickness near the output end of the waveguide such that an evanescent tail of the light in the core penetrates into the out-coupling medium and such that light transmits from the substantially planar core into the out-coupling medium at an out-of-plane propagation angle formed with respect to a plane of the substantially planar core and the at least one cladding;
at least one facet on the out-coupling medium oriented at an angle with respect to the substantially planar core such that the light that has left the substantially planar core passes through the out-coupling medium and impinges on the at least one facet, wherein the light then leaves the waveguide through the at least one facet in an out-of-plane propagation angle; and
at least one electrode for receiving at least one voltage selected to control the magnitude of the propagation angle.