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US 7,116,878 B2Granted
Optical waveguide structure
AssigneeMesophotonics Limited
InventorsMajd Zoorob, Martin Charlton, Greg Parker
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AssigneeMesophotonics Limited
InventorsMajd Zoorob, Martin Charlton, Greg Parker
Estimating the term…
A waveguide structure (200) according to the invention comprises a core layer (210), a cladding layer (206) and a buffer layer (208). Sub-regions (204) are formed in the cladding layer (206) but not in the core layer (210). In one dimensional applications the sub-regions are slots: in two dimensional applications the sub-regions are rods. The rods or slots may be air-filled or filled with an in-fill material, (e.g. Si). The in-fill material, if present, enhances the contrast in dielectric constant between sub-regions (204) and the core layer (210). Sub-regions (204) may furthermore be formed in the portion of the buffer layer neighbouring the core layer. Slots or rods in the buffer may be air-filled or filled by an in-fill material. Substantially complete confinement of the mode in the core can be assured while still maintaining the ability to interact with the field within the photonic band structure region. Rather than perturb the majority of the field (which is confined in the core), it is possible to interact with the evanescent field in the cladding layer (or the buffer layer) without substantially affecting mode confinement.
A planar waveguide structure comprising:
A planar waveguide structure comprising:
A planar waveguide structure comprising:
A method of manufacturing planar waveguide structures having a core layer and a cladding layer, said cladding layer having first and second opposing external surfaces, said first surface of said cladding layer contiguous with a first surface of said core layer, said core layer having a first refractive index, ncore, and no photonic band structure, the method comprising the steps of:
A method of guiding an optical signal comprising the step of passing an optical signal through a waveguiding region of a planar optical waveguide structure comprising a core layer and a cladding layer, said cladding layer having first and second opposing external surfaces, said first surface of said cladding layer contiguous with a first surface of said core layer, said core layer having a first refractive index, ncore, and no photonic band structure, wherein the cladding layer comprises a first region having a first refractive index ncladding, where ncore>ncladding, and a plurality of sub-regions in said first region having a second refractive index nsub, said sub-regions arranged in a plane, said plane is parallel to said first surface, each of said sub-regions extending from said second surface of said cladding layer in a direction perpendicular to said plane, and wherein the array of sub-regions comprises a photonic band structure within a region of the cladding layer causing a contrast in effective mode index adjacent the cladding photonic band structure region between the first region and the sub-regions which perturbs only an evanescent field of the optical signal propagating through the core layer.
Dependencies are inferred from the claim text.