Patent US4787693A successfully refreshed from Google Patents.
US4787693A
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Passive star coupler
Assignee: Nokia Bell Labs
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Filing: 1987-11-02
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Granted: 1988-11-29
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Expires: 2007-11-02
Abstract
Abstract A star coupler for a single-mode-fiber optical local area network which reduces the amount of fiber required by a factor of two and diminishes the number of components by one-half. This savings in fiber and components is effected by "reflecting" signals which appear at various locations of the network back toward the input ports. The arrangement forms a broadcast-type of local area network where a message transmitted by any user can be received by all users.
Inventors
- 👤 Herwig W. Kogelnik
- 👤 Adel A. M. Saleh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:14
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; H; H04; H04Q; H04Q11/00; H04Q11/0001; G02B6/26; G02B6/28; G02B6/2804; G02B6/2817; G02B6/2821
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
102 words
A single mode fiber passive star coupler having a number of ports n equal to an arbitrary multiple (l) of a perfect square (m 2 ) of an arbitrary number (m); characterized by ml transmissive m×m stars, the ports i of the l transmissive m×m stars of l-group i, i=1,2, . . . , m, are coupled together via a reflective l star; and the ports i of the l transmissive m×m stars of l group #j,i,j=1,2 . . . , m, i≠j, are coupled via(m-1) transmissive l×l stars to ports j of the l transmissive m×m stars of the l-group #i.
Claim 2
Dependent Claim
102 words
A single mode fiber passive star coupler having a number of ports n equal to an arbitrary multiple (l) of a perfect square (m 2 ) of an arbitrary number (m); characterized by ml transmissive m×m stars, the ports i of the l transmissive m×m stars of l-group i, i=1,2, . . . , m, are coupled together via a reflective l star; and the ports i of the l transmissive m×m stars of l group #j,i,j=1,2 . . . , m, i≠j, are coupled via(m-1) transmissive l×l stars to ports j of the l transmissive m×m stars of the l-group #i.
Claim 3
Dependent Claim
107 words
A single mode fiber passive star coupler having a number of ports equal to an arbitrary multiple (l) of a perfect square (m 2 ) of an arbitrary number (m) characterized by a first group of transmissive m×m star coupler; a second group of transmissive m×m star coupler, transmissive l×l star interposed between selected output ports of the first group of transmissive stars and selected output ports of the second group of transmissive stars, a first reflective star coupled to selective ports of the first group of transmissive star couplers, and a second reflective star coupled to selective ports of the second group of transmissive star couplers.
Claim 4
Dependent Claim
107 words
A single mode fiber passive star coupler having a number of ports equal to an arbitrary multiple (l) of a perfect square (m 2 ) of an arbitrary number (m) characterized by a first group of transmissive m×m star coupler; a second group of transmissive m×m star coupler, transmissive l×l star interposed between selected output ports of the first group of transmissive stars and selected output ports of the second group of transmissive stars, a first reflective star coupled to selective ports of the first group of transmissive star couplers, and a second reflective star coupled to selective ports of the second group of transmissive star couplers.
Claim 5
Dependent Claim
50 words
The star coupler of claim 2 further characterized in that for a reflective star coupler having n ports where n is equal to an arbitrary (l) multiple (m) of a perfect square (n=lm 2 ), there are ml transmissive m×m stars, m(m-1)/2 transmissive l×l stars, and m reflective l stars.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-11-29 | 1992-05-30 | 1992-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-29 | 1996-05-30 | 1996-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-29 | 2000-05-30 | 2000-11-29 | $7700.00 | Window Closed / Lapsed |