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US4887879A Expired / Lapsed US ⏱️ 0.0 years remaining

Fiber optic tap

Assignee: Columbia University
•
Filing: 1988-01-25
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Granted: 1989-12-19
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Expires: 2008-01-25
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Abstract

Abstract A passive fiber optic tap for a single mode optical fiber is disclosed which utilizes cladding modes induced within the fiber by a microbender. The fiber has a symmetrically circular hour glass shaped notch for tapping radiation from the cladding mode and a detector converts light into an electrical signal. Large tapping ratios, low excess loss and structural compatibility with integrated circuity is obtained.

Inventors

  • 👤 Paul R. Prucnal
  • 👤 Stuart DS. Elby
  • 👤 Edward E. Harstead

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 23:00
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/14; G02B6/24; G02B6/42; G02B6/4201; G02B6/4286; G02B6/4287; G02B6/429; G02B6/4289

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 80 words
A passive optical tap for a single-mode optical fiber for optically transferring optical information from a source optically connected to said fiber to a light detector which comprises: means for inducing cladding modes within the fiber; detector means for converting light into an electrical signal; means for optically coupling the fiber to said detector means to couple energy from the induced cladding modes to the detector means, wherein the means for optically coupling comprises notch means formed in the fiber.
Claim 2
Dependent Claim 80 words
A passive optical tap for a single-mode optical fiber for optically transferring optical information from a source optically connected to said fiber to a light detector which comprises: means for inducing cladding modes within the fiber; detector means for converting light into an electrical signal; means for optically coupling the fiber to said detector means to couple energy from the induced cladding modes to the detector means, wherein the means for optically coupling comprises notch means formed in the fiber.
Claim 3
Dependent Claim 24 words
A passive optical tap as defined in claim 1, wherein the means for optically coupling comprises a reduced diametrical notch formed in the fiber.
Claim 4
Dependent Claim 15 words
A passive optical tap as defined in claim 2, wherein the notch is circularly symmetrical.
Claim 5
Dependent Claim 19 words
A passive optical tap as defined in claim 2, wherein the means for inducing cladding modes comprises a microbender.
Claim 6
Dependent Claim 32 words
A passive optical tap as defined in claim 2, wherein the microbender comprises a mode-scrambler which induces cladding modes and causes redistribution of the cladding modes into a steady state modal distribution.
Claim 7
Dependent Claim 20 words
A passive optical tap as defined in claim 1, wherein the detector means for converting light comprises an integrated photodetector.
Claim 8
Dependent Claim 21 words
A passive optical tap as defined in claim 6, wherein the detector means for converting light comprises a p-n junction detector.
Claim 9
Dependent Claim 40 words
A passive optical tap as defined in claim 2, including a semiconductor wafer having a cavity etched from one surface of the wafer to another surface of the wafer, and wherein said fiber is received to pass through said cavity.
Claim 10
Dependent Claim 23 words
A passive optical tap as defined in claim 8, wherein the semiconductor wafer is a silicon wafer and the electroconductive metal is aluminum.
Claim 11
Dependent Claim 27 words
A passive optical tap as defined in claim 8, wherein an electroductive metal is deposited on the surface of the wafer around the opening of the cavity.
Claim 12
Dependent Claim 23 words
A passive optical tap as defined in claim 10, wherein the semiconductive wafer is gallium arsenide, and the electroconductive metal is gold germanium.
Claim 13
Dependent Claim 23 words
A passive optical tap as defined in claim 2, wherein the cladding of the fiber is chemically etched away to form the notch.
Claim 14
Dependent Claim 30 words
A passive optical tap as defined in claim 1, wherein the fiber has a glass core diameter of about 4 um and an outside (cladding) diameter of about 80 um.
Claim 15
Dependent Claim 38 words
A passive optical tap as defined in claim 2, wherein the fiber has a glass core diameter of about 4 um and an outside (cladding) diameter of about 80 um and a notch depth of about 20 um.
Claim 16
Dependent Claim 23 words
A passive optical tap as defined in claim 4, wherein the microbender includes means for adjusting the extent of microbend in the fiber.
Claim 17
Dependent Claim 26 words
A passive optical tap as defined in claim 8, wherein the detector means comprises a p-n junction detector formed on the inside surface of the cavity.
Claim 18
Dependent Claim 143 words
A passive optical tap for a single-mode optical fiber for optically transferring optical information from a source optically connected to said fiber to a light detector, which comprises: a semiconductor wafer having a cavity etched from one surface of the wafer to another surface of the wafer; detector means for converting light into an electrical signal, comprising a p-n junction detector on the inside surface of the cavity, and wherein an electroconductive metal is deposited on the opening of the cavity in electrical contact with the p-n junction; microbender means for inducing cladding modes within the fiber; optical coupling means for optically coupling the fiber to said detector means to couple energy from the induced cladding modes to the detector means, said optical coupling means comprising a reduced diametrical notch formed in the fiber said fiber notch being located in said wafer cavity.
Claim 19
Dependent Claim 143 words
A passive optical tap for a single-mode optical fiber for optically transferring optical information from a source optically connected to said fiber to a light detector, which comprises: a semiconductor wafer having a cavity etched from one surface of the wafer to another surface of the wafer; detector means for converting light into an electrical signal, comprising a p-n junction detector on the inside surface of the cavity, and wherein an electroconductive metal is deposited on the opening of the cavity in electrical contact with the p-n junction; microbender means for inducing cladding modes within the fiber; optical coupling means for optically coupling the fiber to said detector means to couple energy from the induced cladding modes to the detector means, said optical coupling means comprising a reduced diametrical notch formed in the fiber said fiber notch being located in said wafer cavity.

References Cited (Backward Citations)

US4557552A Cited
US4557550A Cited
US4586783A Cited
US4781428A Cited
US4741585A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-12-18 1993-06-19 1993-12-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-12-18 1997-06-19 1997-12-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-12-18 2001-06-19 2001-12-19 $7700.00 Window Closed / Lapsed

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