Patent US4893889A successfully refreshed from Google Patents.
US4893889A
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Optical attenuator
Assignee: Seiko Instruments Inc
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Filing: 1988-08-29
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Granted: 1990-01-16
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Expires: 2008-08-29
Abstract
Abstract An optical attenuator for attenuating optical power by providing an air gap between coupled fiber ends. Both the end faces are allowed to have an inclination, thereby providing an optical attenuator with less reflected light and multiple reflection between coupled fibers.
Inventors
- 👤 Toyokazu Iwakiri
- 👤 Akira Sugiyama
- 👤 Yoshio Kashima
- 👤 Ikuo Betsui
- 👤 Nobuo Suzuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:18
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/36; G02B6/38; G02B6/3807; G02B6/3873; G02B6/3874; G02B6/3875; G02B6/26; G02B6/262; G02B6/264; G02B6/266; G02B6/3833; G02B6/3846; G02B6/3869; G02B6/381; G02B6/3818; G02B6/3822; G02B6/3863
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
29 words
An optical attenuator comprising a pair of optical fibers having mutually facing non-parallel end surfaces separated by an air gap and having non facing end surfaces thereof polished sphericallly.
Claim 2
Dependent Claim
29 words
An optical attenuator comprising a pair of optical fibers having mutually facing non-parallel end surfaces separated by an air gap and having non facing end surfaces thereof polished sphericallly.
Claim 3
Dependent Claim
24 words
The optical attenuator as claimed in claim 1, wherein each of said mutually facing non-parallel end surfaces is provided with an antireflection coating thereon.
Claim 4
Dependent Claim
23 words
The optical attenuator of claim 1, in which at least said mutually facing end surfaces of said optical fibers are substantially coaxially aligned.
Claim 5
Dependent Claim
29 words
The optical attenuator of claim 3, in which each of said mutually facing non-parallel end surfaces is polished obliquely relative to the longitudinal axis of its respective optical fiber.
Claim 6
Dependent Claim
15 words
The optical attenuator of claim 4, in which said optical fibers are substantially coaxially aligned.
Claim 7
Dependent Claim
35 words
The optical attenuator of claim 1, comprising encasement means for supporting said optical fibers along a central axis thereof, said encasement means surrounding said optical fibers and having mutually facing non-parallel surfaces defining said gap.
Claim 8
Dependent Claim
28 words
The optical attenuator of claim 6, in which said encasement means comprises oppositely facing substantially spherical end surfaces corresponding to said spherically polished surfaces of said optical fibers.
Claim 9
Dependent Claim
16 words
The optical attenuator of claim 7, comprising means for holding said encasement means in coaxial alignment.
References Cited (Backward Citations)
US4384203A
Cited
US4695126A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-15 | 1993-07-17 | 1994-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-15 | 1997-07-17 | 1998-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-15 | 2001-07-17 | 2002-01-16 | $7700.00 | Window Closed / Lapsed |