Suppression of stimulated Brillouin scattering in optical fiber
AssigneeCorning Incorporated
InventorsAlan Frank Evans, Carlton Maurice Truesdale
Life of this patent
Estimating the term…
Abstract
Suppression of stimulated Brillouin scattering (SBS) by broadening the energy spectrum of participating SBS photons and/or phonons is achieved in an optical fiber having a core with both radially nonuniform viscosity and CTE profiles provided by alternating layers of glass modifying dopants such as phosphorous and fluorine. The nonuniform thermal expansion and viscosity profiles impart a residual, permanent, nonuniform stress in the fiber. The SBS suppressing effect provided by the nonuniform stress can be controlled and enhanced by applying a uniform or nonuniform tensile force to the fiber as it is being drawn. A preform for the fiber is also disclosed.
Claims10
An optical waveguide fiber having increased power handling capacity, comprising:
- a core region including a doped region consisting essentially of at least one first annular compositional layer having a CTE and a viscosity that are substantially uniform in an axial direction, and at least one second annular compositional layer immediately adjacent said first layer having a different CTE and a different viscosity than said first layer that are substantially uniform in an axial direction, wherein each of said first and second layers has a thickness of 0.05 μm to 0.5 μm;
- and
- a cladding region surrounding an outermost part of said core region, whereby the fiber exhibits a permanent radially nonuniform CTE and viscosity profile.
An optical waveguide fiber having increased power handling capacity, comprising:
- a core region including a doped region consisting essentially of at least one first annular compositional layer having a CTE and a viscosity that are substantially uniform in an axial direction, and at least one second annular compositional layer immediately adjacent said first layer having a different CTE and a different viscosity than said first layer that are substantially uniform in an axial direction;
- and
- a cladding region surrounding an outermost part of said core region, whereby the fiber exhibits a permanent radially nonuniform CTE and viscosity profile, wherein said doped region is substantially located at a radial distance from the center of the core where an area-averaged optical power peak, proportional to |E|2rdr, has a maximum value, where (E) represents an electric field value, (r) is the radius of the core, and (dr) is the differential radius.
An optical waveguide fiber having increased power handling capacity, comprising:
- a core region including a doped region consisting essentially of at least one first annular compositional layer having a CTE and a viscosity that are substantially uniform in an axial direction, and at least one second annular compositional layer immediately adjacent said first layer having a different CTE and a different viscosity than said first layer that are substantially uniform in an axial direction, wherein each of said first and second layers has a thickness of 0.05 μm to 0.5 μm;
- and
- a cladding region surrounding an outermost part of said core region, whereby the fiber exhibits a permanent radially nonuniform CTE and viscosity profile, wherein the first layer is selected from a group consisting essentially of:
- SiO2+GeO2+P2O5;
- SiO2+GeO2+F2;
- SiO2+GeO2;
- and
- the second layer is selected from a group consisting essentially of:
- SiO2;
- and
- SiO2+F2, and
- wherein the composition consisting essentially of SiO2+GeO2+P2O5 consists essentially (in weight %) of (57-92) SiO2, (8-40) GeO2, and (0-3) P2O5;
- the composition consisting essentially of SiO2+GeO2+F2 consists essentially (in weight %) of (58-92) SiO2, (8-40) GeO2, and (0-2) F2;
- the composition consisting essentially of SiO2+GeO2 consists essentially (in weight %) of (60-92) SiO2 and (8-40) GeO2;
- and, the composition consisting essentially of SiO2+F2 consists essentially (in weight %) of (98-100) SiO2 and (0-2) F2.
An optical waveguide fiber having increased power handling capacity, comprising:
- a core region including a doped region consisting essentially of at least one first annular compositional layer having a CTE and a viscosity that are substantially uniform in an axial direction, and at least one second annular compositional layer immediately adjacent said first layer having a different CTE and a different viscosity than said first layer that are substantially uniform in an axial direction;
- and
- a cladding region surrounding an outermost part of said core region, whereby the fiber exhibits a permanent radially nonuniform CTE and viscosity profile, wherein the first layer is selected from a group consisting essentially of:
- SiO2+GeO2+P2O5;
- SiO2+GeO2+F2;
- and
- the second layer is selected from a group consisting essentially of:
- SiO2;
- and
- SiO2+F2, wherein each of said first and second layers is less than 0.5 μm thick.
An optical waveguide fiber having increased power handling capacity, comprising:
- a core region including a doped region consisting essentially of at least one first annular compositional layer having a CTE and a viscosity that are substantially uniform in an axial direction, and at least one second annular compositional layer immediately adjacent said first layer having a different CTE and a different viscosity than said first layer that are substantially uniform in an axial direction, wherein each of said first and second layers has a thickness of 0.05 μm to 0.5 μm;
- and
- a cladding region surrounding an outermost part of said core region, whereby the fiber exhibits a permanent radially nonuniform CTE and viscosity profile having a residual strain, ΔL/L, of at least 0.001 at an interface of the first and second layer.
An optical waveguide fiber having an increased power handling capacity, comprising:
- a core having both a radially nonuniform CTE profile and viscosity profile in a part of said core intermediate a center and an outermost region of the core;
- and
- a cladding surrounding the outermost region of the core, wherein the radially nonuniform part of the core is located at a radial distance from the center of the core where an area-averaged optical power peak, proportional to |E|2rdr, has a maximum value, where (E) represents an electric field value, (r) is the radius of the core, and (dr) is the differential radius.
Dependencies are inferred from the claim text.