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US 2006/0185397 A1Published application
Multimode optical fiber and method for manufacturing same
AssigneeFurukawa Electric North America, Inc.
InventorsJerry Baumgart, George Oulundsen, Man Yan
Life of this patent
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Abstract
An improved MCVD process reduces a rippling structure in the refractive-index profile of a graded-index, multiple-mode optical fiber by incorporating N2O, CO, or NF3 gas in the gas stream during deposition of a soot sub-layer from which the optical fiber is formed. The soot sub-layer is sintered to form a glass sub-layer during deposition of a subsequent soot sub-layer. A dopant species is incorporated in each soot sub-layer during deposition. Fibers made from the doped glass sub-layers have a graded refractive-index profile that is near-parabolic in shape and that has significantly reduced rippling compared to profiles observed for fibers prepared conventionally.
Claims17
A method for reducing ripples in a refractive-index profile of a multimode optical fiber, the method comprising the steps of:
- (a) providing a substrate;
- (b) flowing along the substrate a gas mixture that includes O2, a gaseous silicon-bearing compound, a gaseous dopant-bearing compound, and N2O;
- (c) moving a heat source along the substrate to cause the silicon-bearing compound and the dopant-bearing compound to form oxide soot particles, wherein the soot particles deposit as a first doped soot layer on the substrate;
- (d) adjusting the gas mixture by adjusting a quantity of one or more of the O2, the gaseous silicon-bearing compound, the gaseous dopant-bearing compound, and the N2O flowing along the substrate;
- and
- (e) moving the heat source along the substrate to cause the silicon-bearing compound and the dopant-bearing compound of the adjusted gas mixture to form oxide soot particles with a different dopant concentration, wherein the soot particles with the different dopant concentration deposit as a second doped soot layer on top of a first doped glass layer formed from the first doped soot layer,
- wherein, when the heat source is moved along the substrate, a previously deposited soot layer is sintered to form a glass layer.
4 more elements
A method for reducing ripples in a refractive-index profile of a multimode optical fiber, the method comprising the steps of:
- (a) providing a substrate;
- (b) flowing along the substrate a gas mixture that includes O2, a gaseous silicon-bearing compound, a gaseous dopant-bearing compound, and NF3;
- (c) moving a heat source along the substrate to cause the silicon-bearing compound and the dopant-bearing compound to form oxide soot particles, wherein the soot particles deposit as a first doped soot layer on the substrate;
- (d) adjusting the gas mixture by adjusting a quantity of one or more of the O2, the gaseous silicon-bearing compound, the gaseous dopant-bearing compound, and the NF3 flowing along the substrate;
- and
- (e) moving the heat source along the substrate to cause the silicon-bearing compound and the dopant-bearing compound of the adjusted gas mixture to form oxide soot particles with a different dopant concentration, wherein the soot particles with the different dopant concentration deposit as a second doped soot layer on top of a first doped glass layer formed from the first doped soot layer,
- wherein, when the heat source is moved along the substrate, a previously deposited soot layer is sintered to form a glass layer.
4 more elements
A method for reducing ripples in a refractive-index profile of a multimode optical fiber, the method comprising the steps of:
- (a) providing a substrate;
- (b) flowing along the substrate a gas mixture that includes O2, a gaseous silicon-bearing compound, a gaseous dopant-bearing compound, and CO;
- (c) moving a heat source along the substrate to cause the silicon-bearing compound and the dopant-bearing compound to form oxide soot particles, wherein the soot particles deposit as a first doped soot layer on the substrate;
- (d) adjusting the gas mixture by adjusting a quantity of one or more of the O2, the gaseous silicon-bearing compound, the gaseous dopant-bearing compound, and the CO flowing along the substrate;
- and
- (e) moving the heat source along the substrate to cause the silicon-bearing compound and the dopant-bearing compound of the adjusted gas mixture to form oxide soot particles with a different dopant concentration, wherein the soot particles with the different dopant concentration deposit as a second doped soot layer on top of a first doped glass layer formed from the first doped soot layer,
- wherein, when the heat source is moved along the substrate, a previously deposited soot layer is sintered to form a glass layer.
4 more elements
A method for reducing ripples in a refractive-index profile of a multimode optical fiber, the method comprising the steps of:
- (a) providing a tubular substrate;
- (b) flowing through the substrate a gas mixture that includes O2, a gaseous silicon-bearing compound, a gaseous dopant-bearing compound, and N2O;
- (c) heating the gas mixture to cause the silicon-bearing compound and the dopant-bearing compound to form oxide soot particles, wherein the soot particles deposit as a doped soot layer on the substrate;
- (d) sintering the doped soot layer to form a glass layer;
- (e) adjusting the gas mixture by adjusting a quantity of one or more of the O2, the gaseous silicon-bearing compound, the gaseous dopant-bearing compound, and the N2O flowing along the substrate;
- (f) heating the adjusted gas mixture to cause the silicon-bearing compound and the dopant-bearing compound of the adjusted gas mixture to form oxide soot particles with a different dopant concentration, wherein the soot particles with the different dopant concentration deposit as a doped soot layer on top of the glass layer;
- and
- (g) repeating steps (d), (e), and (f) to form a plurality of glass layers on the substrate.
5 more elements
A method for reducing ripples in a refractive-index profile of a multimode optical fiber, the method comprising the steps of:
- (a) providing a tubular substrate;
- (b) flowing through the substrate a gas mixture that includes O2, a gaseous silicon-bearing compound, a gaseous dopant-bearing compound, and NF3;
- (c) heating the gas mixture to cause the silicon-bearing compound and the dopant-bearing compound to form oxide soot particles, wherein the soot particles deposit as a doped soot layer on the substrate;
- (d) sintering the doped soot layer to form a glass layer;
- (e) adjusting the gas mixture by adjusting a quantity of one or more of the O2, the gaseous silicon-bearing compound, the gaseous dopant-bearing compound, and the NF3 flowing along the substrate;
- (f) heating the adjusted gas mixture to cause the silicon-bearing compound and the dopant-bearing compound of the adjusted gas mixture to form oxide soot particles with a different dopant concentration, wherein the soot particles with the different dopant concentration deposit as a doped soot layer on top of the glass layer;
- and
- (g) repeating steps (d), (e), and (f) to form a plurality of glass layers on the substrate.
5 more elements
A method for reducing ripples in a refractive-index profile of a multimode optical fiber, the method comprising the steps of:
- (a) providing a tubular substrate;
- (b) flowing through the substrate a gas mixture that includes O2, a gaseous silicon-bearing compound, a gaseous dopant-bearing compound, and CO;
- (c) heating the gas mixture to cause the silicon-bearing compound and the dopant-bearing compound to form oxide soot particles, wherein the soot particles deposit as a doped soot layer on the substrate;
- (d) sintering the doped soot layer to form a glass layer;
- (e) adjusting the gas mixture by adjusting a quantity of one or more of the O2, the gaseous silicon-bearing compound, the gaseous dopant-bearing compound, and the CO flowing along the substrate;
- (f) heating the adjusted gas mixture to cause the silicon-bearing compound and the dopant-bearing compound of the adjusted gas mixture to form oxide soot particles with a different dopant concentration, wherein the soot particles with the different dopant concentration deposit as a doped soot layer on top of the glass layer;
- and
- (g) repeating steps (d), (e), and (f) to form a plurality of glass layers on the substrate.
5 more elements
Dependencies are inferred from the claim text.