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US4304489A Expired / Lapsed US ⏱️ 0.0 years remaining

System for measuring an optical loss in a single mode optical fiber

Assignee: KDDI Corp
•
Filing: 1980-04-29
•
Granted: 1981-12-08
•
Expires: 2000-04-29
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Abstract

Abstract An optical loss in a single mode optical device is measured by utilizing multi-mode equipment. The present system comprises of an optical source (1), a sample (30) to be tested, a reference optical attenuator (31) for replacing the optical loss in the sample (30), a first optical switch (40) provided between the optical source (1) and the sample (30) through a single mode optical fiber, a second optical switch (41) provided between the sample (30) and the light receiver (2) through the multi-mode optical fiber, said reference optical attenuator (31) being provided between the first optical switch (40) and the second optical switch (41) so that the optical path is switched either to the sample (30) or to the reference attenuator (31), the optical fiber between the sample (30) and the second optical switch (41) and the optical fiber connected to the input and the output of the reference attenuator (31) being a multi-mode optical fiber.

Inventors

  • 👤 Hiroharu Wakabayashi
  • 👤 Yasuhiko Niiro

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 06:24
CPC Classifications
G; G01; G01M; G01M11/00; G01M11/30; G01M11/33

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 118 words
A system for measuring an optical loss in a single mode optical fiber comprising an optical source (1), a sample (30) to be tested, a reference attenuator (31) for replacing the optical loss in the sample (30), a first switch (40) provided between the optical source (1) and the sample (30) through a single mode optical fiber, a second optical switch (41) provided between the sample (30) and the light receiver (2) through an optical fiber, and at least the optical fiber between the sample (30) and the second switch (41) and the optical fiber between the second switch (41) and the light receiver (2) having a larger numerical aperture than that of the sample to be tested.
Claim 2
Independent Claim 118 words
A system for measuring an optical loss in a single mode optical fiber comprising an optical source (1), a sample (30) to be tested, a reference attenuator (31) for replacing the optical loss in the sample (30), a first switch (40) provided between the optical source (1) and the sample (30) through a single mode optical fiber, a second optical switch (41) provided between the sample (30) and the light receiver (2) through an optical fiber, and at least the optical fiber between the sample (30) and the second switch (41) and the optical fiber between the second switch (41) and the light receiver (2) having a larger numerical aperture than that of the sample to be tested.
Claim 3
Dependent Claim 48 words
A system for measuring an optical loss in a single mode optical fiber according to claim 1, wherein said optical fiber between the sample (30) and the second switch (41), and the optical fiber between the second switch (41) and the light receiver (2) are multi-mode optical fibers.
Claim 4
Dependent Claim 22 words
The invention as defined in the claim 1, wherein said reference attenuator (31) is inserted between the first and the second switches.
Claim 5
Dependent Claim 28 words
The invention as defined in the claim 1, wherein said reference attenuator (31) is inserted between the output of the second switch (41) and the light receiver (2).
Claim 6
Dependent Claim 26 words
The invention as defined in the claim 1, wherein said reference attenuator is an electrical attenuator and is provided at the output of the light receiver.
Claim 7
Dependent Claim 32 words
The invention as defined in the claim 1, wherein the first switch 40 has the input single mode optical fiber and the output single mode optical fiber positioned on a straight line.
Claim 8
Dependent Claim 26 words
The invention as defined in the claim 3, wherein said reference attenuator (31) is connected to the first and the second switches through multi-mode optical fibers.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-12-07 1985-06-08 1985-12-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-12-07 1989-06-08 1989-12-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-12-07 1993-06-08 1993-12-08 $7700.00 Window Closed / Lapsed

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