Thermally stabilized waveguides
An apparatus comprising a planar optical waveguide having an optical core and optical cladding next to the optical core. The optical core or cladding includes a plurality of particles therein. Each particle has a nucleus and polymeric molecules permanently bonded to the nucleus to form a shell. A plurality of nuclei are dispersed in said core or cladding.
1. A method of fabricating a planar optical waveguide, comprising:
chemically bonding a polymer to a surface of a nucleus to form a particle having a polymer shell;
forming a layer of said particles on a substrate, said layer comprising a plurality of nuclei dispersed in said polymer; and
selectively removing portions of said layer to form a planar optical waveguide,
wherein a volume fraction of said nucleus and a volume fraction of said shell in said planar optical waveguide are selected to result in about equal and opposite contributions to a thermo-optic coefficient (TOC) of said waveguide by said volume fractions.
2. The method as recited in claim 1 , wherein a sum of a product of said volume fraction of said nucleus multiplied by said TOC of said nucleus and a product of said volume fraction of said shell multiplied by said TOC of said shell is less than about 1 E-6° C −1 .
3. The method as recited in claim 1 , wherein said chemically bonding includes forming a covalent bond between said polymeric molecules and said surface.
4. The method as recited in claim 1 , wherein said polymer is formed by anionic polymerization from an initiator chemically bonded to a surface of said nucleus.
5. The method as recited in claim 1 , wherein said polymer is cross-linked after forming said layer.
6. The method as recited in claim 1 , wherein said polymer is formed in a dispersion prior to said chemically bonding.
7. The method as recited in claim 1 , wherein said polymer comprises poly(dimethyl siloxane).
8. The method as recited in claim 1 , wherein said waveguide is configured to operate in the optical C-band.
9. A method of fabricating a planar optical waveguide, comprising:
chemically bonding a polymer to a surface of a nucleus to form a particle having a polymer shell, a bulk thermo-optic coefficient (TOC) of said nucleus and a bulk TOC of said shell having opposite signs;
forming a layer of said particles on a substrate, said layer comprising a plurality of nuclei dispersed in said polymer, a volume fraction of said nuclei and a volume fraction of said polymer in said layer having about equal and opposite contributions to said TOC of said waveguide; and
selectively removing portions of said layer to form a planar optical waveguide.
10. The method as recited in claim 9 , wherein said chemically bonding includes forming a covalent bond between said polymeric molecules and said surface.
11. The method as recited in claim 9 , wherein said polymer is cross-linked after forming said layer.
12. The method as recited in claim 9 , wherein said polymer comprises poly(dimethyl siloxane).
13. The method as recited in claim 9 , wherein said waveguide is configured to operate in the optical C-band.
14. A method of fabricating a planar optical waveguide, comprising:
covalently bonding a polymer to a surface of a nucleus to form a particle having a polymer shell;
forming an optical core or cladding on a substrate, said optical core or cladding including a plurality of particles dispersed in said polymer;
selectively removing portions of said core or cladding to form a planar optical waveguide,
wherein a volume fraction of said nucleus and a volume fraction of said shell in said optical core or cladding are selected to result in about equal and opposite contributions to a thermo-optic coefficient (TOC) of said waveguide by said volume fractions.
15. The method as recited in claim 14 , wherein said polymer is cross-linked after forming said layer.
16. The method as recited in claim 14 , wherein said polymer comprises poly(dimethyl siloxane).
17. The method as recited in claim 14 , wherein said waveguide is configured to operate in the optical C-band.