Liquid crystal planar non-blocking NxN cross-connect
OwnerThomas M. Leslie, Robert G. Lindquistinventors
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Abstract
A non-blocking N×N cross-connect is provided that has an array of liquid crystal (LC) switches in a grid of planar optical waveguides within a light optical circuit (LOC). LC filled trenches are used in a planar optical waveguide and each trench provides the functionality of a waveguide polarization splitter, a transverse electric (TE) switch cross point, a transverse magnetic (TM) switch cross point, or a waveguide polarization combiner. By combining these elements, a cross-connect system is fabricated.
Claims45
An optical device for directing a light signal, comprising:
- an optical path for propagating the light signal;
- a trench formed in the optical path, said trench including a surface region;
- an alignment layer disposed on said surface region;
- and
- a liquid crystal material disposed in said trench, said liquid crystal material having a plurality of molecules that are aligned in a first direction by said alignment layer.
The optical device according to claim l, wherein the optical device is disposed within one of a polarization splitter, a polarization combiner, a TM switch, a TE switch, a variable optical attenuator, a signal splitter, and an N×N TE-TM array.
A method of directing a light signal in an optical device, said optical device having a first optical path and a second optical path, said method comprising:
- forming a trench in a cross-point, wherein said cross-point is a location where the first optical path intersects the second optical path;
- forming an alignment layer on a surface region of the trench;
- disposing a liquid crystal material having a plurality of molecules in the trench, wherein said alignment layer causes said plurality of molecules to align in a first direction;
- and
- applying a voltage to said liquid crystal material to thereby change an alignment of said plurality of molecules from said first direction to a second direction to cause a portion of the light signal to be directed from the first optical path into the second optical path.
A method of directing a light signal in an optical device, said optical device including an optical path, a trench formed in said optical path, and an alignment layer disposed on a surface of said trench, said method comprising:
- disposing a switch element in the trench, said switch element including a plurality of liquid crystal molecules that are aligned in a first direction by the alignment layer when no electrical energy is applied to said switch element;
- and
- applying electrical energy to said switch element to thereby cause said plurality of molecules to align in a second direction.
An optical device for directing a light signal, said optical device including a substrate having an optical waveguide layer disposed thereon, said optical device comprising:
- at least one first electrode disposed between the substrate and the optical waveguide;
- a trench formed in the optical waveguide, said trench having a surface area;
- a first alignment layer disposed on the surface area of said trench;
- a liquid crystal material disposed in said trench and covering said first alignment layer;
- a top plate connected to the substrate;
- and
- a second alignment layer disposed on the top plate and adjacent to said liquid crystal material.
A liquid crystal cross-connect device, comprising:
- an input port for receiving light;
- a polarization splitter to split the received light into transverse magnetic (TM) and transverse electric (TE) components;
- a TM switch array connected to receive the TM components from the polarization splitter;
- a TE switch array connected to receive the TE components from the polarization splitter;
- a polarization combiner coupled to the TM switch array and the TE switch array to combine the outputs of the TM switch array and the TE switch array;
- and
- an output port coupled to the polarization combiner.
Dependencies are inferred from the claim text.