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US 10,571,628 B2Granted
Low loss optical fiber with core codoped with two or more halogens
AssigneeCorning Incorporated
InventorsDana Craig Bookbinder, Steven Bruce Dawes, Ming-Jun Li, Pushkar Tandon
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Abstract
A co-doped optical fiber is provided having an attenuation of less than about 0.17 dB/km at a wavelength of 1550 nm. The fiber includes a core in the fiber having a graded refractive index profile with an alpha of greater than 5. The fiber also includes a cladding in the fiber that surrounds the core addition, the core includes silica that is co-doped with two or more halogens.
Claims26
A single mode optical fiber, comprising:
- a core having a graded refractive index profile with an alpha of less than 5;
- and
- the cladding comprising a depressed cladding region and an outer cladding region in contact with and surrounding the depressed cladding region, wherein the core has a relative refractive index of greater than +0.25% compared to that of the outer cladding region, wherein the core comprises silica co-doped with a first halogen and a second halogen, wherein the concentrations of said first and said second halogen within the core are non-uniform, such that:
- (a) the ratio of maximum and minimum concentration of the first halogen in the core is at least 3,
- (b) the ratio of maximum and minimum concentration of the second halogen in the core is at least 3,
- (c) the concentration within the core of one halogen increases as distance from the center of the core increases,
- (d) and the concentration within the core of the other halogen decreases as distance from the center of the core increases, wherein a fiber has an attenuation of less than about 0.17 dB/km at a wavelength of 1550 nm.
4 more elements
A single mode optical fiber, comprising:
- a core having a graded refractive index profile with an alpha of less than 5;
- and
- a cladding surrounding the core, the cladding comprising a moat and comprising a moat and an outer cladding region;
- wherein the core has a relative refractive index of greater than +0.05% compared to pure silica, wherein the core comprises silica co-doped with chlorine and fluorine, wherein the concentrations of fluorine and chlorine within the core are non-uniform, such that:
- (a) difference between maximum and minimum concentration of chlorine in the core is at least 0.4 wt %,
- (b) difference between maximum and minimum concentration of fluorine in the core is at least 0.45 wt %,
- (c) the maximum amount of chlorine in the core is at least 0.7 wt %, and
- (d) the maximum of fluorine in the core is at least 0.75 wt %,
- wherein the fiber has an attenuation of less than about 0.17 dB/km at a wavelength of 1550 nm.
6 more elements
A method of making core cane comprising:
- (i) exposing a silica soot preform to at least one of:
- chlorine dopant precursor, bromine dopant precursor, or a combination thereof at a temperature between 900° C. and 1350° C., wherein the partial pressure of the chlorine or bromine dopant precursor is greater than 0.5 atm, to form Cl and/or Br doped soot preform;
- (ii) exposing the Cl and/or Br doped soot preform to a fluorine dopant precursor at a temperature between 1275° C. and 1450 C, wherein the partial pressure of the fluorine dopant precursor is greater than 0.1 atm, to form a co-doped doped preform;
- (iii) exposing the co-doped preform to a temperature above 1400° C. to completely sinter the codoped preform and to form a sintered core preform.
1 more element
Dependencies are inferred from the claim text.