EP0147225A2
Expired / Lapsed
EP
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Method of forming an optical fiber
Assignee: Corning Glass Works
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Filing: 1984-12-21
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Granted: —
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Expires: 2004-12-21
Abstract
Abstract A single-mode optical waveguide is constructed in a manner such that the core thereof is subjected to a stress-induced birefingence. A single-mode optical fiber preform (52) is formed by a CVD process. A pair of longitudinally extending holes (58,78) is formed on opposite sides of the core, spaced slightly therefrom. A stress rod (60, 81) having a TCE different from that of the cladding portion of the preform is inserted into each hole. The space between the holes and the rods is evacuated. The resultant composite structure is drawn into an optical fiber. A similar method is used to form a fiber having multiple light conducting cores, this method differing in that the rods which are inserted into the holes are formed of a glass having a refractive index greater than that of the cladding portion of the preform.
Inventors
- 👤 George Edward Berkey
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-30 13:39
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/10; C03B37/12; C03B37/01; C03B37/012; C03B37/01205; C03B37/01211; C03B37/01222; C03B20/00; C03B37/01217; C03B2203/00; C03B2203/30; C03B2203/31; C03B2203/34
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
76 words
A method of forming an optical fiber comprising the steps of providing a cylindrical preform of glass having a first composition, forming in said preform a plurality of longitudinally-extending holes, providing a plurality of rods of glass having a composition different from that of said first composition, inserting one of said rods into each of said holes, and drawing the resulting assembly to bond together said glass rods and said preform into an integral optical fiber.
Claim 2
Independent Claim
76 words
A method of forming an optical fiber comprising the steps of providing a cylindrical preform of glass having a first composition, forming in said preform a plurality of longitudinally-extending holes, providing a plurality of rods of glass having a composition different from that of said first composition, inserting one of said rods into each of said holes, and drawing the resulting assembly to bond together said glass rods and said preform into an integral optical fiber.
Claim 3
Dependent Claim
49 words
A method in accordance with claim 1 wherein prior to the step of drawing, a vacuum connection is affixed to that end of said preform opposite the end from which said fiber is drawn and the space between each rod and the adjacent walls of said holes is evacuated.
Claim 4
Dependent Claim
52 words
A method in accordance with.claim 2 wherein the step of affixing a vacuum connection to said preform comprises forming at one end of said preform an endface that is substantially perpendicular to the axis thereof and fusing to said endface a thin-walled glass cylinder, said vacuum connection being connected to said cylinder.
Claim 5
Dependent Claim
18 words
A method in accordance with claim 3, wherein said endface is formed by severing an end of said-preform.
Claim 6
Independent Claim
41 words
A method in accordance with any preceding claim, wherein the step of providing a plurality of rods comprises providing rods having a glass core surrounded by a layer of cladding glass having a composition different from that of said glass core.
Claim 7
Independent Claim
34 words
A method in accordance with any preceding claim, wherein the step of providing a plurality of rods comprises providing rods having a glass core surrounded by a layer of glass of said first composition.
Claim 8
Independent Claim
44 words
A method in accordance with any preceding claim, wherein the step of forming a plurality of holes comprises forming holes of non-circular cross-section and the step of providing rods comprises providing rods having a cross-sectional configuration substantially the same as that of said holes.
Claim 9
Independent Claim
40 words
A method in accordance with any one of claims 1 to 4 wherein the step of providing a plurality of rods comprises providing a plurality of rods of glass having a refractive index greater than that of said preform glass.
Claim 10
Independent Claim
75 words
A method in accordance with any one of claims 1 to 4, wherein the step of providing a preform comprises providing a preform having a centrally disposed glass core surrounded by a layer of cladding glass having a refractive index lower than that of the core glass, and wherein the step of providing a plurality of rods comprises providing rods of glass having a refractive index which is greater than that of said cladding glass.
Claim 11
Independent Claim
59 words
A method in accordance with any one of claims 1 to 4, wherein the step of providing a cylindrical preform comprises providing a preform having a uniform composition throughout, and wherein the step of providing a plurality of rods comprises providing a plurality of rods of glass having a refractive index greater than that of said first glass composition.
Claim 12
Independent Claim
56 words
A method in accordance with claim lO wherein the step of providing a plurality of rods comprises providing rods having a core of glass having a refractive index greater than that of said first glass composition, said core being surrounded by a layer of cladding glass having a composition different from that of said glass core.
Claim 13
Dependent Claim
50 words
A method in accordance with claim 10 wherein the step of providing a plurality of rods comprises providing rods having a core of glass having a refractive index greater than that of said first glass composition, said core being surrounded by a layer of cladding glass of said first composition.
Claim 14
Independent Claim
113 words
A method in accordance with any one of claims 1 to 7, wherein the step of providing a preform comprises providing a preform having a centrally disposed glass core surrounded by a layer of cladding glass of said first composition, said preform cladding glass having a refractive index lower than that of the core glass, the step of forming longitudinally-extending holes comprises forming in said cladding glass on diametrically opposed sides of said preform core a pair of longitudinally-extending holes, and wherein the step of providing a plurality of rods comprises providing a pair of rods of glass having a thermal coefficient of expansion which differs from that of said preform cladding glass.
Claim 15
Dependent Claim
65 words
A method in accordance with claim 13, wherein the step of providing a plurality of rods comprises providing rods having a cross-sectional area slightly smaller than that of said holes except at one end thereof where the rod cross-sectional area enlarges to a value greater than that of said holes, the enlarged region of said rods protruding above said preform during the step of drawing.
Claim 16
Dependent Claim
37 words
A method in accordance with claim 13 or 14, wherein the step of forming a plurality of holes further comprises forming a second pair of diametrically opposed holes which are equally spaced from said pair of holes.
Claim 17
Dependent Claim
75 words
A method in accordance with claim 15 wherein said pair of rods are formed of a glass having a thermal coefficient of expansion greater than that of said preform cladding, said method further comprising the steps of providing a second pair of rods of glass having a thermal coefficient of expansion less than that of said preform cladding; and inserting one of said second pair of rods into each of said second pair of holes.
Claim 18
Independent Claim
200 words
A method of forming a single-mode optical fiber having a polarization retaining characteristics comprising the steps of providing a glass preform having a centrally disposed glass core surrounded by a layer of cladding glass having a refractive index lower than that of the core glass, forming on one end of said preform a flat surface that is substantially perpendicular to the axis thereof, forming in said cladding glass on diametrically opposed sides of said core a pair of longitudinally-extending holes, fusing to said endface a thin-walled glass cylinder, providing a pair of rods of glass having a thermal coefficient of expansion which differs from that of said cladding glass, the diameters of said rods being less than that of said holes, enlarging the diameter at one end of each of said rods, inserting one of said rods into each of said holes such that the enlarged end of each rod protrudes from the respective hole, affixing a vacuum connection to said cylinder and evacuating.the space within said cylinder and the space between said rods and the adjacent walls of said holes, and drawing the resulting assembly to bond together said glass rods and said preform into an integral optical fiber.
Claim 19
Independent Claim
200 words
A method of forming a single-mode optical fiber having a polarization retaining characteristics comprising the steps of providing a glass preform having a centrally disposed glass core surrounded by a layer of cladding glass having a refractive index lower than that of the core glass, forming on one end of said preform a flat surface that is substantially perpendicular to the axis thereof, forming in said cladding glass on diametrically opposed sides of said core a pair of longitudinally-extending holes, fusing to said endface a thin-walled glass cylinder, providing a pair of rods of glass having a thermal coefficient of expansion which differs from that of said cladding glass, the diameters of said rods being less than that of said holes, enlarging the diameter at one end of each of said rods, inserting one of said rods into each of said holes such that the enlarged end of each rod protrudes from the respective hole, affixing a vacuum connection to said cylinder and evacuating.the space within said cylinder and the space between said rods and the adjacent walls of said holes, and drawing the resulting assembly to bond together said glass rods and said preform into an integral optical fiber.
Claim 20
Dependent Claim
72 words
A method in accordance with claim 17 - wherein the step of providing a pair of rods comprises forming by a vapor deposition technique a pair of glass rods each having a core region of glass, the thermal coefficient of expansion of which is different from that of said preform cladding, said core region being surrounded by a cladding region of glass having a composition different from that of said core region.
Claim 21
Dependent Claim
173 words
1 9 . A method of forming an optical fiber having multiple light transmitting cores, comprising providing a preform of glass having a first composition, forming on one end of said preform a flat surface that is substantially perpendicular to the axis thereof, forming in said preform a plurality of longitudinally-extending holes, fusing to said endface a thin-walled glass cylinder, providing a pair of rods of glass having a refractive index which is greater than that of said cladding glass, the diameters of said rods being less than that of said holes, enlarging the diameter at one end of each of said rods, inserting one of said rods into each of said holes such that the enlarged end of each rod protrudes from the respective hole, affixing a vacuum . connection to said cylinder and evacuating the space within said cylinder and the space between said rods and the adjacent walls of said holes, and drawing the resulting assembly to bond together said glass rods and said preform into an integral optical fiber.
Claim 22
Dependent Claim
173 words
1 9 . A method of forming an optical fiber having multiple light transmitting cores, comprising providing a preform of glass having a first composition, forming on one end of said preform a flat surface that is substantially perpendicular to the axis thereof, forming in said preform a plurality of longitudinally-extending holes, fusing to said endface a thin-walled glass cylinder, providing a pair of rods of glass having a refractive index which is greater than that of said cladding glass, the diameters of said rods being less than that of said holes, enlarging the diameter at one end of each of said rods, inserting one of said rods into each of said holes such that the enlarged end of each rod protrudes from the respective hole, affixing a vacuum . connection to said cylinder and evacuating the space within said cylinder and the space between said rods and the adjacent walls of said holes, and drawing the resulting assembly to bond together said glass rods and said preform into an integral optical fiber.
Claim 23
Dependent Claim
73 words
A method in accordance with claim 19, wherein -the step of providing two glass rods comprises forming by a vapor deposition technique a pair of glass rods having a core region of glass, the refractive index of which is greater than that of said preform cladding, said core region being surrounded by a cladding region of glass having a composition the refractive index of which is less than that of said core region.
References Cited (Backward Citations)
No citation records indexed.
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