Optical fiber gratings with index matched polymer coating for cladding mode suppression
AssigneeLucent Technologies Inc.
InventorsArturo Hale, Thomas Andrew Strasser, Paul Stephen Westbrook
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Abstract
In accordance with the invention, an optical fiber Bragg grating comprises a length of gloss optical fiber having a core, a Bragg grating formed along the core, a glass cladding and a polymer coating on the cladding having an index of refraction matched to that the cladding. Such index matching can reduce the cladding mode loss by a factor of four over current levels. A preferred coating material comprises fluorinated urethane acrylate.
Claims23
An improved optical fiber Bragg grating device for operating over a temperature range comprising a length of glass optical fiber having a core, a Bragg grating formed along the core, and a glass cladding around the core, the improvement comprising:
- a polymer coating around the glass cladding for reducing cladding mode loss, the polymer having an index of refraction above that of the cladding for at least part of the temperature range and below that of the cladding for at least part of the temperature range.
An improved optical fiber Bragg grating device for operating over a temperature range comprising a length of glass optical fiber having a core, a Bragg grating formed along the core, and a glass cladding around the core, the improvement comprising:
- a polymer coating around the glass cladding for reducing cladding mode loss,
- wherein the polymer coating comprises the polymerization product of (a) 5 to 100% by weight of a fluorine-containing urethane (mmeth)acrylate;
- (b) up to about 95% by weight of a mono-functional or di-functional (meth)acrylate monomer;
- and (c) up to about 95% by weight of an aliphatic or aromatic urethane acrylate oligomer.
An improved optical fiber Bragg grating device for operating over a temperature range comprising a length of glass optical fiber having a core, a Bragg grating formed along the core, and a glass cladding around the core, the improvement comprising:
- a polymer coating around the glass cladding for reducing cladding mode loss, wherein the polymer coating comprises a urethane acrylate or (meth)acrylate prepared by reacting a fluorinated alcohol, a diisocyanate, and a hydroxy-containing photocurable hydrocarbon.
An improved optical fiber Bragg grating device comprising a length of glass optical fiber having a core, a Bragg grating formed along the core, and a glass cladding around the core, the improvement comprising:
- a polymer coating around the glass cladding, the polymer coating being prepared with a formulation comprising a blending and/or polymerization product of (a) 40 to 85% by weight of the reaction product of a fluorinated alcohol, a diisocyanate, and a hydroxy-containing photocurable hydrocarbon;
- (b) up to 60% by weight of a urethane acrylate oligomer;
- (c) up to 60% by weight hexanediol diacrylate;
- and (d) about 0.01 to 10% of a photoinitiator,
- wherein the glass cladding has an index of refraction ncladding, the polymer coating has an index of refraction npolymer, and −0.01<npolymer−ncladding<0.02, such that the polymer coating reduces cladding mode loss.
Dependencies are inferred from the claim text.