US4763976A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Connector employing mode field modification
Assignee: Corning Glass Works
•
Filing: 1987-05-21
•
Granted: 1988-08-16
•
Expires: 2007-05-21
Abstract
Abstract Disclosed is a mode field modifier for use with an optical fiber having a core and a cladding of outside diameter d. The modifier comprises a modifier core having a refractive index n 1 . Surrounding the modifier core is first cladding layer having a refractive index n 2 that is less n 1 . On the surface of the first cladding layer is a second cladding layer having a refractive index n 3 which is less than n 2 . The modifier is tapered intermediate its ends whereby it has a large diameter end and a small diameter end. The diameters of at least the core and first cladding layer at the large diameter end are greater than the corresponding diameters at the small end. The diameter D 1 of the first cladding layer at the large diameter end is greater than d. An axially disposed hole in the large diameter end receives a fiber which is held in such alignment with the mode field modifier that it is in light coupling relationship with the modifier core. The mode field of a signal coupled from the fiber to the mode field modifier expands as it propagates though the tapered portion of the modifier to the small diameter end. An in-line coupler between two optical fibers is effected by connecting together in axial alignment two such mode field modifiers with their small diameter ends adjacent one another.
Inventors
- 👤 Daniel A. Nolan
- 👤 Carlton M. Truesdale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:03
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/36; G02B6/38; G02B6/3807; G02B6/3833; G02B6/3855; G02B6/3858; G02B6/3859; G02B6/262; G02B6/42; G02B6/4201; G02B6/4202
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
218 words
A mode field modifier for use with an optical fiber having a core and a cladding of outside diameter d, said modifier comprising a modifier core having a refractive index n 1 , a first cladding layer surrounding said modifier core, said first cladding layer having a refractive index n 2 that is less than n 1 , a second cladding layer on the surface of said first cladding layer, the refractive index n 3 of said second cladding layer being less than n 2 , said modifier being tapered intermediate its ends whereby it has a large diameter end and a small diameter end, the diameters of at least said core and said first cladding layer at said large diameter end are greater than the corresponding diameters at said small diameter end, whereby the mode field of an optical signal propagating in one end of said modifier is modified as said signal propagates through the tapered portion of said modifier, the diameter D 1 of said first cladding layer at said large diameter end being greater than d, and means for positioning a fiber at said large diameter end in light coupling relationship with said modifier core, said means for positioning comprising a hole in said large diameter end, said hole being concentric with said modifier core.
Claim 2
Dependent Claim
218 words
A mode field modifier for use with an optical fiber having a core and a cladding of outside diameter d, said modifier comprising a modifier core having a refractive index n 1 , a first cladding layer surrounding said modifier core, said first cladding layer having a refractive index n 2 that is less than n 1 , a second cladding layer on the surface of said first cladding layer, the refractive index n 3 of said second cladding layer being less than n 2 , said modifier being tapered intermediate its ends whereby it has a large diameter end and a small diameter end, the diameters of at least said core and said first cladding layer at said large diameter end are greater than the corresponding diameters at said small diameter end, whereby the mode field of an optical signal propagating in one end of said modifier is modified as said signal propagates through the tapered portion of said modifier, the diameter D 1 of said first cladding layer at said large diameter end being greater than d, and means for positioning a fiber at said large diameter end in light coupling relationship with said modifier core, said means for positioning comprising a hole in said large diameter end, said hole being concentric with said modifier core.
Claim 3
Dependent Claim
35 words
A mode field modifier in accordance with claim 1 wherein said first cladding layer comprises inner and outer layers of glass, said inner layer being more soluble in a given solvent than said outer layer.
Claim 4
Dependent Claim
27 words
A mode field modifier in accordance with claim 2 wherein the refractive index of said outer layer is substantially the same as that of said inner layer.
Claim 5
Dependent Claim
25 words
A mode field modifier in accordance with claim 2 wherein the refractive index of said outer layer is less than that of said inner layer.
Claim 6
Independent Claim
343 words
A device for connecting first and second single-mode optical fibers of diameter d, said device comprising first and second mode field modifiers, each having a modifier core having a refractive index n 1 , a first cladding layer surrounding said modifier core, said first cladding layer having a refractive index n 2 that is less than n 1 , a second cladding layer on the surface of said first cladding layer, the refractive index n 3 of said second cladding layer being less than n 2 , said modifier being tapered intermediate its ends whereby it has a large diameter end and a small diameter end, the diameters of at least said core and said first cladding layer at said large diameter end are greater than the corresponding diameters at said small diameter end, whereby the mode field of an optical signal propagating in one end of said modifier is modified as said signal propagates through the tapered portion of said modifier, the diameters of said core and first cladding layer at said small diameter end being sufficiently small that the field of a signal propagating in said large diameter end of said coupler toward the small diameter end thereof is no longer confined to said core and first cladding but it spreads and is effectively guided by the waveguide consisting of said first and second claddings, the diameter D 1 of said first cladding layer at said large diameter end being greater than d, whereby an enhanced enlargement of the mode field diameter of said single-mode signal is obtained, means for positioning said first optical fiber at said large diameter end of said first modifier in light coupling relationship with said first modifier core, means for positioning said second optical fiber at said large diameter end of said second modifier in light coupling relationship with said second modifier core, and means for positioning the small diameter end of said first modifier adjacent the small diameter end of said second modifier with the axes of said first and second modifiers in substantial alignment.
Claim 7
Independent Claim
343 words
A device for connecting first and second single-mode optical fibers of diameter d, said device comprising first and second mode field modifiers, each having a modifier core having a refractive index n 1 , a first cladding layer surrounding said modifier core, said first cladding layer having a refractive index n 2 that is less than n 1 , a second cladding layer on the surface of said first cladding layer, the refractive index n 3 of said second cladding layer being less than n 2 , said modifier being tapered intermediate its ends whereby it has a large diameter end and a small diameter end, the diameters of at least said core and said first cladding layer at said large diameter end are greater than the corresponding diameters at said small diameter end, whereby the mode field of an optical signal propagating in one end of said modifier is modified as said signal propagates through the tapered portion of said modifier, the diameters of said core and first cladding layer at said small diameter end being sufficiently small that the field of a signal propagating in said large diameter end of said coupler toward the small diameter end thereof is no longer confined to said core and first cladding but it spreads and is effectively guided by the waveguide consisting of said first and second claddings, the diameter D 1 of said first cladding layer at said large diameter end being greater than d, whereby an enhanced enlargement of the mode field diameter of said single-mode signal is obtained, means for positioning said first optical fiber at said large diameter end of said first modifier in light coupling relationship with said first modifier core, means for positioning said second optical fiber at said large diameter end of said second modifier in light coupling relationship with said second modifier core, and means for positioning the small diameter end of said first modifier adjacent the small diameter end of said second modifier with the axes of said first and second modifiers in substantial alignment.
Claim 8
Dependent Claim
211 words
A mode field modifier for use with an optical fiber having a core and a cladding of outside diameter d, said modifier comprising a modifier core having a refractive index n 1 , a first cladding layer surrounding said modifier core, said first cladding layer having a refractive index n 2 that is less than n 1 , a second cladding layer on the surface of said first cladding layer, the refractive index n 3 of said second cladding layer being less than n 2 , the ratio (n 2 -n 3 )/n 2 being no smaller than 0.5%, said modifier being tapered intermediate its ends whereby it has a large diameter end and a small diameter end, the diameters of at least said core and said first cladding layer at said large diameter end are greater than the corresponding diameters at said small diameter end, whereby the mode field of an optical signal propagating in one end of said modifier is modified as said signal propagates through the tapered portion of said modifier, the diameter D 1 of said first cladding layer at said large diameter end being greater than d, and means for positioning a fiber at said large diameter end in light coupling relationship with said modifier core.
Claim 9
Dependent Claim
211 words
A mode field modifier for use with an optical fiber having a core and a cladding of outside diameter d, said modifier comprising a modifier core having a refractive index n 1 , a first cladding layer surrounding said modifier core, said first cladding layer having a refractive index n 2 that is less than n 1 , a second cladding layer on the surface of said first cladding layer, the refractive index n 3 of said second cladding layer being less than n 2 , the ratio (n 2 -n 3 )/n 2 being no smaller than 0.5%, said modifier being tapered intermediate its ends whereby it has a large diameter end and a small diameter end, the diameters of at least said core and said first cladding layer at said large diameter end are greater than the corresponding diameters at said small diameter end, whereby the mode field of an optical signal propagating in one end of said modifier is modified as said signal propagates through the tapered portion of said modifier, the diameter D 1 of said first cladding layer at said large diameter end being greater than d, and means for positioning a fiber at said large diameter end in light coupling relationship with said modifier core.
Claim 10
Dependent Claim
248 words
A mode field modifier for use with an optical fiber having a core and a cladding of outside diameter d, said modifier comprising a modifier core having a refractive index n 1 , a first cladding layer surrounding said modifier core, said first cladding layer having a refractive index n 2 that is less than n 1 , a second cladding layer on the surface of said first cladding layer, the refractive index n 3 of said second cladding layer being less than n 2 , said modifier being tapered intermediate its ends whereby it has a large diameter end and a small diameter end, the diameters of at least said core and said first cladding layer at said large diameter end are greater than the corresponding diameters at said small diameter end, whereby the mode field of an optical signal propagating in one end of said modifier is modified as said signal propagates through the tapered portion of said modifier, the diameter D 1 of said first cladding layer at said large diameter end being greater than d, and means for positioning a fiber at said large diameter end in light coupling relationship with said modifier core, said fiber forming the central portion of said mode field modifier and said first cladding layer comprising the cladding of said fiber and a further layer on the surface of said fiber cladding, said further layer having a refractive index equal to or less than that of said fiber cladding.
Claim 11
Dependent Claim
248 words
A mode field modifier for use with an optical fiber having a core and a cladding of outside diameter d, said modifier comprising a modifier core having a refractive index n 1 , a first cladding layer surrounding said modifier core, said first cladding layer having a refractive index n 2 that is less than n 1 , a second cladding layer on the surface of said first cladding layer, the refractive index n 3 of said second cladding layer being less than n 2 , said modifier being tapered intermediate its ends whereby it has a large diameter end and a small diameter end, the diameters of at least said core and said first cladding layer at said large diameter end are greater than the corresponding diameters at said small diameter end, whereby the mode field of an optical signal propagating in one end of said modifier is modified as said signal propagates through the tapered portion of said modifier, the diameter D 1 of said first cladding layer at said large diameter end being greater than d, and means for positioning a fiber at said large diameter end in light coupling relationship with said modifier core, said fiber forming the central portion of said mode field modifier and said first cladding layer comprising the cladding of said fiber and a further layer on the surface of said fiber cladding, said further layer having a refractive index equal to or less than that of said fiber cladding.
Claim 12
Dependent Claim
250 words
A mode field modifier for use with an optical fiber having a core and a cladding of outside diameter d, said modifier comprising a modifier core having a refractive index n 1 , a first cladding layer surrounding said modifier core, said first cladding layer having a refractive index n 2 that is less than n 1 , a second cladding layer on the surface of said first cladding layer, the refractive index n 3 of said second cladding layer being less than n 2 , said modifier being tapered intermediate its ends whereby it has a large diameter end and a small diameter end, the diameters of at least said core and said first cladding layer at said large diameter end being greater than the corresponding diameters at said small diameter end, the diameters of said core and first cladding layer at said small diameter end being sufficiently small that the field of a signal propagating in said large diameter end of said coupler toward the small diameter end thereof is no longer confined to said core and first cladding but it spreads and is effectively guided by the waveguide consisting of said first and second claddings, the diameter D 1 of said first cladding layer at said large diameter end being greater than d, whereby an enhanced enlargement of the mode field diameter of said single-mode signal is obtained, and means for positioning a fiber at said large diameter end in light coupling relationship with said modifier core.
Claim 13
Dependent Claim
250 words
A mode field modifier for use with an optical fiber having a core and a cladding of outside diameter d, said modifier comprising a modifier core having a refractive index n 1 , a first cladding layer surrounding said modifier core, said first cladding layer having a refractive index n 2 that is less than n 1 , a second cladding layer on the surface of said first cladding layer, the refractive index n 3 of said second cladding layer being less than n 2 , said modifier being tapered intermediate its ends whereby it has a large diameter end and a small diameter end, the diameters of at least said core and said first cladding layer at said large diameter end being greater than the corresponding diameters at said small diameter end, the diameters of said core and first cladding layer at said small diameter end being sufficiently small that the field of a signal propagating in said large diameter end of said coupler toward the small diameter end thereof is no longer confined to said core and first cladding but it spreads and is effectively guided by the waveguide consisting of said first and second claddings, the diameter D 1 of said first cladding layer at said large diameter end being greater than d, whereby an enhanced enlargement of the mode field diameter of said single-mode signal is obtained, and means for positioning a fiber at said large diameter end in light coupling relationship with said modifier core.
Claim 14
Dependent Claim
259 words
A mode field modifier for use with a single-mode optical fiber having a core and a cladding of outside diameter d, said modifier comprising a modifier core having a refractive index n 1 , a first cladding layer surrounding said modifier core, said first cladding layer having a refractive index n 2 that is less than n 1 , a second cladding layer on the surface of said first cladding layer, the refractive index n 3 of said second cladding layer being less than n 2 , said modifier being tapered intermediate its ends whereby it has a large diameter end and a small diameter end, the diameters of at least said core and said first cladding layer at said large diameter end being greater than the corresponding diameters at said small diameter end, the diameters of said core and first cladding layer at said small diameter end being sufficiently small that the field of a single-mode signal propagating in said core and first cladding layer at said large diameter end of said coupler toward the small diameter end thereof is no longer confined to said core and first cladding but it spreads and is effectively guided by the waveguide consisting of said first and second claddings, the diameter D 1 of said first cladding layer at said large diameter end being greater than d, whereby an enhanced enlargement of the mode field diameter of said single-mode signal is obtained, and means for positioning a fiber at said large diameter end in light coupling relationship with said modifier core.
Claim 15
Dependent Claim
259 words
A mode field modifier for use with a single-mode optical fiber having a core and a cladding of outside diameter d, said modifier comprising a modifier core having a refractive index n 1 , a first cladding layer surrounding said modifier core, said first cladding layer having a refractive index n 2 that is less than n 1 , a second cladding layer on the surface of said first cladding layer, the refractive index n 3 of said second cladding layer being less than n 2 , said modifier being tapered intermediate its ends whereby it has a large diameter end and a small diameter end, the diameters of at least said core and said first cladding layer at said large diameter end being greater than the corresponding diameters at said small diameter end, the diameters of said core and first cladding layer at said small diameter end being sufficiently small that the field of a single-mode signal propagating in said core and first cladding layer at said large diameter end of said coupler toward the small diameter end thereof is no longer confined to said core and first cladding but it spreads and is effectively guided by the waveguide consisting of said first and second claddings, the diameter D 1 of said first cladding layer at said large diameter end being greater than d, whereby an enhanced enlargement of the mode field diameter of said single-mode signal is obtained, and means for positioning a fiber at said large diameter end in light coupling relationship with said modifier core.
References Cited (Backward Citations)
US3779628A
Cited
JPS53116850A
Cited
US4678267A
Cited
US4252403A
Cited
US4415227A
Cited
US4521070A
Cited
US4465335A
Cited
US4654532A
Cited
US4688884A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-08-16 | 1992-02-15 | 1992-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-16 | 1996-02-15 | 1996-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-16 | 2000-02-15 | 2000-08-16 | $7700.00 | Window Closed / Lapsed |