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US 6,393,185 B1Granted
Differential waveguide pair
AssigneeSparkolor Corporation
InventorDavid A. G. Deacon
Life of this patent
Estimating the term…
Abstract
An asymmetric waveguide pair (1440) with a differential thermal response has an optical coupling frequency that may be thermo-optically tuned. Tuning may also be accomplished by applying an electric field (1445) across a liquid crystal portion (1442) of the waveguide structure. The waveguide pair may include a grating and be used as a frequency selective coupler for an optical resonator. The differential waveguide pair may also be used as a temperature or electric field sensor, or it may be used in a waveguide array to adjust a phase relationship, e.g. in an arrayed waveguide grating.
Claims73
A differential waveguide pair device comprising:
- a substrate;
- a first cladding layer disposed over said substrate;
- a first elongated core material region disposed on said first cladding layer;
- a second elongated core material region disposed on said first cladding layer horizontally displaced from but proximate to said first elongated core material region for optical coupling therebetween;
- and
- a second cladding layer disposed above said first cladding layer over and around at least one of said elongated core material regions, said second cladding layer having a different thickness in a vicinity of said first elongated core material region relative to a vicinity of said second elongated core material region, said core material regions characterized by higher refractive indices than said cladding layers thereby defining first and second optical waveguides for propagation of optical energy therein, said different second cladding layer thicknesses in the vicinities of said first and second core material regions resulting in different sensitivities of optical propagation constants for said first and second optical waveguides to an externally variable field, and wherein the coupling between said first and second waveguides varies substantially with said changes in said externally variable field.
3 more elements
A differential waveguide device comprising:
- a first waveguide segment having a waveguide core and clad material surrounding the core, the first waveguide segment characterized by a first lowest order mode profile and a first rate of change in a first effective index of refraction with increases in applied field;
- a second waveguide segment having a waveguide core and clad material surrounding the core, the second waveguide segment horizontally displaced from but proximate to said first waveguide for coupling optical energy and characterized by a second lowest order mode profile and a second rate of change in a second effective index of refraction with increases in applied field, the clad material surrounding the core of the first waveguide segment having a different thickness than the clad material surrounding the core of the second waveguide segment;
- an actuator electrode disposed to apply a field that is substantially identical in said first and second waveguide segments;
- wherein the magnitude of the first rate is substantially different from the magnitude of the second rate, and wherein a difference between the first and second effective indices may be modified by varying the applied field.
1 more element
A thermally adjustable differential waveguide coupler device comprising:
- a substrate;
- a first cladding material layer disposed on said substrate and characterized by a first refractive index;
- a second cladding material layer disposed on said substrate and characterized by a second refractive index;
- a third cladding material layer disposed adjacent said second cladding and characterized by a temperature dependent third refractive index;
- a first elongated region of a core material characterized by a core refractive index larger than the first and second refractive indices interposed between said first and second claddings to form a first waveguide, said first waveguide characterized by a first effective index of refraction having a first rate of change with increases in temperature, said first waveguide further characterized by a first overlap factor of a first mode profile with said third cladding layer;
- a second elongated region of the core material interposed between said first and second claddings to form a second waveguide disposed proximate to and substantially parallel to said first waveguide, said second waveguide characterized by a second effective index of refraction having a second rate of change with increases in temperature, said second waveguide further characterized by a second overlap factor of a second mode profile with said third cladding layer;
- and
- a heater electrode thermally coupled to said first and second waveguides;
- wherein said second cladding layer is thicker in a vicinity of said second waveguide than in a vicinity of said first waveguide, the first overlap factor is larger than the second overlap factor, and the magnitude of the first rate is substantially different from the magnitude of the second rate;
- and
- wherein an optical coupling between said first and second waveguides is modified by actuating said heater electrode thereby modifying the difference between the first and second effective indices.
8 more elements
A field adjustable differential waveguide coupler device comprising:
- a substrate;
- a first cladding material layer disposed on said substrate and characterized by a first refractive index;
- a second cladding material layer disposed on said substrate and characterized by a second refractive index;
- a third cladding material layer disposed adjacent said second cladding and characterized by a third refractive index that is dependent upon an applied field;
- a first elongated region of a core material characterized by a core refractive index larger than the first and second refractive indices interposed between said first and second claddings to form a first waveguide, said first waveguide characterized by a first effective index of refraction having a first rate of change with increases in applied field, said first waveguide further characterized by a first overlap factor of a first lowest order mode profile with said third cladding layer;
- a second elongated region of the core material interposed between said first and second claddings to form a second waveguide disposed proximate to said first waveguide for optical coupling therebetween, said second waveguide characterized by a second effective index of refraction having a second rate of change with increases in applied field, said second waveguide further characterized by a second overlap factor of a second lowest order mode profile with said third cladding layer;
- and
- an actuator electrode disposed to apply a field in said first and second waveguide;
- wherein said second cladding layer is thicker in a vicinity of said second waveguide than in a vicinity of said first waveguide, the first overlap factor is larger than the second overlap factor, and the magnitude of the first rate is substantially different from the magnitude of the second rate, and wherein a difference between the first and second effective indices may be modified by varying the applied field.
6 more elements
An optical temperature sensor element comprising:
- a substrate;
- a first cladding material layer disposed on said substrate and characterized by a first refractive index;
- a second cladding material layer disposed on said substrate and characterized by a second refractive index;
- a third cladding material layer disposed adjacent said second cladding and characterized by a temperature-dependent third refractive index;
- and
- a first elongated region of core material characterized by a core refractive index larger than the first and second refractive indices interposed between said first and second cladding layers to form a first waveguide, said first waveguide characterized by a first effective index of refraction, a first rate of change in the first effective index with increases in temperature and a first overlap factor of a first lowest order mode profile with said third cladding layer;
- a second elongated region of core material interposed between said first and second cladding layers to form a second waveguide and disposed proximate to and substantially parallel to said first waveguide for coupling of optical energy, said second waveguide characterized by a second effective index of refraction, a second rate of change in the second effective index with increases in temperature and a second overlap factor of a second lowest order mode profile with said third cladding layer;
- and
- wherein the second cladding layer is thicker in a vicinity of said second waveguide than in a vicinity of said first waveguide, the first overlap factor is larger than the second overlap factor, the magnitude of the first rate is substantially different from the magnitude of the second rate, and wherein the optical coupling between said first and second waveguides varies with the temperature dependent difference in the first and second effective indices.
6 more elements
An optical temperature sensor comprising:
- a first waveguide having a first cladding with a first thickness such that the first waveguide is characterized by a first lowest order mode profile and a first rate of change in a first effective index of refraction with increases in temperature;
- a second waveguide horizontally displaced from but proximate to said first waveguide and having a second cladding with a second thickness different from said first thickness such that the second waveguide is characterized by a second lowest order mode profile and a second rate of change in a second effective index of refraction with the increases in temperature;
- wherein the magnitude of the first rate is substantially different from the magnitude of the second rate, and wherein a coupling between said first and second waveguides varies with the temperature dependent difference in the first and second effective indices.
A field sensitive optical device comprising:
- a plurality of horizontally displaced but proximate waveguides characterized by a plurality of lowest order mode profiles, a plurality of effective indices, and a plurality of rates of change of effective index of refraction with increases in an applied field;
- an optical material layer disposed in overlapping relation with said plurality of waveguides, characterized by a material index of refraction and a material rate of change of index with increases in said applied field, and having a plurality of thicknesses at said plurality of waveguides;
- wherein the thickness at an nth one of said plurality of waveguides determines the nth overlap factor with the nth mode profile, and
- wherein at least one of the plurality of thicknesses differs substantially from another of the plurality of thicknesses and the plurality of thicknesses are spatially distributed among the plurality of waveguides to produce a desired pattern of the rates of change in effective index of refraction with increases in said applied field.
1 more element
Dependencies are inferred from the claim text.