US4252403A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coupler for a graded index fiber
Assignee: U S Holding Co Inc
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Filing: 1979-11-06
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Granted: 1981-02-24
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Expires: 1999-11-06
Abstract
Abstract A concentric core fiber having a low numerical aperture has an end face aligned with the end face of a graded index fiber having a high numerical aperture. The inner core of the concentric core fiber is aligned with and faces the central region of the graded index fiber, while the outer core of the concentric core fiber is aligned with the outer periphery of the inner core of the graded index fiber. In this manner, low order modes which propagate in the inner core of the concentric core fiber are coupled to the central region of the graded index fiber. Higher order modes which propagate in the outer core of the concentric core fiber are applied to the inner core of the graded index fiber and propagate at the edges thereof.
Inventors
- 👤 Glenn C. Salisbury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:09
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/262
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
230 words
An optical coupler, comprising: a graded index fiber having a given numerical aperture, said fiber having an annular cross section comprising an inner light conducting core of a given diameter surrounded by an annular concentric cladding layer, which layer is in turn surrounded by an annular substrate layer, said fiber having an end face of said cross section, a concentric core fiber having a numerical aperture less than said given numerical aperture, said fiber having an annular cross section comprising an inner light conducting core of a diameter less than said given diameter, surrounded by an annular isolation zone of a predetermined width, which in turn is surrounded by an outer light conducting core of another width, wherein the overall diameter of said outer core as surrounding said isolation zone surrounding said inner core is relatively equal to said given diameter of said core of said graded index fiber, said concentric fiber having an end face containing said cross section in congruent alignment with the end face of said graded index fiber to cause low order modes propagating in said inner core of said concentric fiber to couple to a central portion of said inner core of said graded fiber, and to cause high order modes propagating in said outer core of said concentric fiber to propagate at the peripheral edges of said inner core of said graded index fiber.
Claim 2
Dependent Claim
230 words
An optical coupler, comprising: a graded index fiber having a given numerical aperture, said fiber having an annular cross section comprising an inner light conducting core of a given diameter surrounded by an annular concentric cladding layer, which layer is in turn surrounded by an annular substrate layer, said fiber having an end face of said cross section, a concentric core fiber having a numerical aperture less than said given numerical aperture, said fiber having an annular cross section comprising an inner light conducting core of a diameter less than said given diameter, surrounded by an annular isolation zone of a predetermined width, which in turn is surrounded by an outer light conducting core of another width, wherein the overall diameter of said outer core as surrounding said isolation zone surrounding said inner core is relatively equal to said given diameter of said core of said graded index fiber, said concentric fiber having an end face containing said cross section in congruent alignment with the end face of said graded index fiber to cause low order modes propagating in said inner core of said concentric fiber to couple to a central portion of said inner core of said graded fiber, and to cause high order modes propagating in said outer core of said concentric fiber to propagate at the peripheral edges of said inner core of said graded index fiber.
Claim 3
Dependent Claim
26 words
The optical coupler according to claim 1 wherein said numerical aperture of said graded index fiber is selected to be between 0.25 to 0.30. to 0.30.
Claim 4
Dependent Claim
31 words
The optical coupler according to claim 1 wherein said numerical aperture of said concentric core fiber is at least five times less than said numerical aperture of said graded index fiber.
Claim 5
Dependent Claim
21 words
The optical coupler according to claim 3 wherein said numerical aperture of said concentric core fiber is between 0.05 and 0.06.
Claim 6
Dependent Claim
31 words
The optical coupler according to claim 1 wherein said graded index fiber further includes an elastomeric annular layer surrounding said substrate layer to restrain excessive bending of said graded index fiber.
Claim 7
Dependent Claim
27 words
The optical coupler according to claim 1 wherein said inner core of said graded index fiber is fabricated from a glass containing germania, silica, boron and phosphor.
Claim 8
Dependent Claim
18 words
The optical coupler according to claim 1 wherein said annular isolation zone is fabricated from a borosilicate glass.
Claim 9
Dependent Claim
22 words
The optical coupler according to claim 1 wherein the diameter of said inner core of said concentric fiber is about 30 microns.
Claim 10
Dependent Claim
23 words
The optical coupler according to claim 8 wherein the diameter of said inner core of said graded index fiber is about 150 microns.
Claim 11
Dependent Claim
22 words
The optical coupler according to claim 1 wherein the width of said outer core of said concentric fiber is about 30 microns.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-02-24 | 1984-08-25 | 1985-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-24 | 1988-08-25 | 1989-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-24 | 1992-08-25 | 1993-02-24 | $7700.00 | Window Closed / Lapsed |