US3633034A
Expired / Lapsed
US
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Multiplexed optical communication system
Assignee: NEC Corp
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Filing: 1969-07-07
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Granted: 1972-01-04
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Expires: 1989-07-07
Abstract
Abstract A time-division, space-division multiplex system employing a fibrous converging light guide having a specific reflective index distribution. Beams of coherent modulated light spatially multiplexed (and if desired, also time-division multiplexed) are impinged upon one end of the guide, each beam having a specific incident angle and position from the axis. The modulated beams are emitted in a spatially multiplexed fashion from the other end of the guide where they are detected.
Inventors
- 👤 Teiji Uchida
- 👤 Motoaki Furukawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:20
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/42; G02B6/4201; G02B6/4204; G02B6/4206
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
184 words
A multiplexed optical communication system comprising: a fibrous converging light guide forming at least a part of a transmission path for said communication system, the refractive index n on the cross section of said guide at a point of distance x from the axis thereof being defined approximately by the expression n na (1- 1/2 a2x2) where na is the refractive index at said axis and a2 is a positive constant, the length of said light guide being N pi /2 a2, where N is an integer; means for impinging a plurality of coherent light beams, each modulated by an information signal to be transmitted, incident upon one end surface of said light guide respectively at predetermined angles of incidence and respectively at points of preselected distances from said axis, so that said light beams may be transmitted therethrough, each such light beam following a separate light path from one another; and means for separately demodulating said coherent light beams separately emanating from the other end surface of said light guide at angles and distances respectively related to those at said one end surface.
Claim 2
Dependent Claim
184 words
A multiplexed optical communication system comprising: a fibrous converging light guide forming at least a part of a transmission path for said communication system, the refractive index n on the cross section of said guide at a point of distance x from the axis thereof being defined approximately by the expression n na (1- 1/2 a2x2) where na is the refractive index at said axis and a2 is a positive constant, the length of said light guide being N pi /2 a2, where N is an integer; means for impinging a plurality of coherent light beams, each modulated by an information signal to be transmitted, incident upon one end surface of said light guide respectively at predetermined angles of incidence and respectively at points of preselected distances from said axis, so that said light beams may be transmitted therethrough, each such light beam following a separate light path from one another; and means for separately demodulating said coherent light beams separately emanating from the other end surface of said light guide at angles and distances respectively related to those at said one end surface.
Claim 3
Dependent Claim
141 words
A multiplexed optical pulse communication system comprising: a fibrous converging light guide, the refractive index n on the cross section of said guide at a point of distance x from the axis thereof being defined approximately by the expression n na(1- 1/2 a2x2) where na is the refractive index of said axis and a2 is a positive constant; means for impinging a plurality of light pulse trains, each modulated by modulating pulse signals to be transmitted, incident upon one end surface of said light guide respectively, said trains having specific phase differences maintained between said pulse signals; means for demodulating said coherent light beams emanating from the other end surface of said light guide to reproduce said information signals in the time-division multiplex fashion; and means for separating in space domain said modulating signals into a plurality of channel information signals.
Claim 4
Dependent Claim
141 words
A multiplexed optical pulse communication system comprising: a fibrous converging light guide, the refractive index n on the cross section of said guide at a point of distance x from the axis thereof being defined approximately by the expression n na(1- 1/2 a2x2) where na is the refractive index of said axis and a2 is a positive constant; means for impinging a plurality of light pulse trains, each modulated by modulating pulse signals to be transmitted, incident upon one end surface of said light guide respectively, said trains having specific phase differences maintained between said pulse signals; means for demodulating said coherent light beams emanating from the other end surface of said light guide to reproduce said information signals in the time-division multiplex fashion; and means for separating in space domain said modulating signals into a plurality of channel information signals.
Claim 5
Dependent Claim
26 words
The multiplexed optical pulse communication system claimed in claim 2, wherein the length of said guide is N pi /2 a2), where N is an integer.
Claim 6
Dependent Claim
171 words
A multiplexed optical pulse communication system comprising: a fibrous converging light guide, the refractive index n on the cross section of said guide at a point of distance x from the axis thereof, being approximately defined by the expression n na (1- 1/2 a2x2) where na is the refractive index at said axis and a2 is a positive constant, the length of said light guide being N pi /2 a2, where N is an integer; means for impinging a plurality of coherent light beams, respectively modulated with modulating pulse signals, incident upon one end surface of said light guide with specific phase differences maintained between said pulse signals; a transmitting optical antenna system for launching said modulated light beams emerging from the other end surface of said light guide into a media; a receiving optical antenna system for receiving light beams from said transmitting antenna; means coupled to said receiving antenna for detecting said modulated light beams in a time-division fashion; and means for separating said detected signals in space domain.
Claim 7
Dependent Claim
171 words
A multiplexed optical pulse communication system comprising: a fibrous converging light guide, the refractive index n on the cross section of said guide at a point of distance x from the axis thereof, being approximately defined by the expression n na (1- 1/2 a2x2) where na is the refractive index at said axis and a2 is a positive constant, the length of said light guide being N pi /2 a2, where N is an integer; means for impinging a plurality of coherent light beams, respectively modulated with modulating pulse signals, incident upon one end surface of said light guide with specific phase differences maintained between said pulse signals; a transmitting optical antenna system for launching said modulated light beams emerging from the other end surface of said light guide into a media; a receiving optical antenna system for receiving light beams from said transmitting antenna; means coupled to said receiving antenna for detecting said modulated light beams in a time-division fashion; and means for separating said detected signals in space domain.
Claim 8
Dependent Claim
26 words
The multiplexed optical pulse communication system claimed in claim 4, wherein the length of said guide is N pi /2 a2, where N is an integer.
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) | 1975-01-03 | 1975-07-05 | 1976-01-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-03 | 1979-07-05 | 1980-01-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-03 | 1983-07-05 | 1984-01-04 | $7700.00 | Window Closed / Lapsed |