Patent US3703640A successfully refreshed from Google Patents.
US3703640A
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US
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Signal spectral multiplexing system
Assignee: Thales SA
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Filing: 1969-12-08
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Granted: 1972-11-21
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Expires: 1989-12-08
Abstract
Abstract A double-diffraction optical system associated with a monochromatic light source, with optical-electrical modulating means and with photo-electric detector means, for effecting the interlaced spectral multiplexing or demultiplexing of a plurality of electrical signals.
Inventors
- 👤 Georges Broussaud
- 👤 Serge Lowenthal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:16
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/28; G02B6/293; G02B6/29346; G02B6/29361; G02B6/29379; G02B6/2938
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
156 words
A spectral multiplexing electro optical apparatus for generating a multiplexed signal whose frequency spectrum comprises interlaced spectral bands respectively bElonging to the frequency spectra of N electrical signals, N being an integer at least equal to two, said multiplexing apparatus comprising : a monochromatic luminous source simultaneously emitting N distinct luminous beams, N electro optical modulators positioned for respectively modulating said N beams, said modulators having respective control inputs respectively receiving said N electrical signals ; N first diffracting systems respectively positioned on the path of said N beams ; an optical interlacing device positioned for receiving the luminous energy diffracted from said N first diffracting systems, said interlacing device supplying an interlaced luminous beam comprising juxtaposed pencils of light respectively diffracted by said N first diffracting systems ; a second diffracting system positioned for receiving said interlaced luminous beam ; and photo-electric means positioned for receiving the diffracted luminous energy emerging from said second system.
Claim 2
Dependent Claim
156 words
A spectral multiplexing electro optical apparatus for generating a multiplexed signal whose frequency spectrum comprises interlaced spectral bands respectively bElonging to the frequency spectra of N electrical signals, N being an integer at least equal to two, said multiplexing apparatus comprising : a monochromatic luminous source simultaneously emitting N distinct luminous beams, N electro optical modulators positioned for respectively modulating said N beams, said modulators having respective control inputs respectively receiving said N electrical signals ; N first diffracting systems respectively positioned on the path of said N beams ; an optical interlacing device positioned for receiving the luminous energy diffracted from said N first diffracting systems, said interlacing device supplying an interlaced luminous beam comprising juxtaposed pencils of light respectively diffracted by said N first diffracting systems ; a second diffracting system positioned for receiving said interlaced luminous beam ; and photo-electric means positioned for receiving the diffracted luminous energy emerging from said second system.
Claim 3
Dependent Claim
156 words
A spectral multiplexing electro optical apparatus for generating a multiplexed signal whose frequency spectrum comprises interlaced spectral bands respectively bElonging to the frequency spectra of N electrical signals, N being an integer at least equal to two, said multiplexing apparatus comprising : a monochromatic luminous source simultaneously emitting N distinct luminous beams, N electro optical modulators positioned for respectively modulating said N beams, said modulators having respective control inputs respectively receiving said N electrical signals ; N first diffracting systems respectively positioned on the path of said N beams ; an optical interlacing device positioned for receiving the luminous energy diffracted from said N first diffracting systems, said interlacing device supplying an interlaced luminous beam comprising juxtaposed pencils of light respectively diffracted by said N first diffracting systems ; a second diffracting system positioned for receiving said interlaced luminous beam ; and photo-electric means positioned for receiving the diffracted luminous energy emerging from said second system.
Claim 4
Dependent Claim
156 words
A spectral multiplexing electro optical apparatus for generating a multiplexed signal whose frequency spectrum comprises interlaced spectral bands respectively bElonging to the frequency spectra of N electrical signals, N being an integer at least equal to two, said multiplexing apparatus comprising : a monochromatic luminous source simultaneously emitting N distinct luminous beams, N electro optical modulators positioned for respectively modulating said N beams, said modulators having respective control inputs respectively receiving said N electrical signals ; N first diffracting systems respectively positioned on the path of said N beams ; an optical interlacing device positioned for receiving the luminous energy diffracted from said N first diffracting systems, said interlacing device supplying an interlaced luminous beam comprising juxtaposed pencils of light respectively diffracted by said N first diffracting systems ; a second diffracting system positioned for receiving said interlaced luminous beam ; and photo-electric means positioned for receiving the diffracted luminous energy emerging from said second system.
Claim 5
Dependent Claim
146 words
A spectral demultiplexing electro optical apparatus for demultiplexing a multiplexed signal as supplied by the spectral multiplexing system as claimed in claim 1, said spectral demultiplexing apparatus comprising a monochromatic luminous source emitting a luminous beam ; an electro optical modulator positioned for modulating said beam, said modulator having a control input for receiving said multiplexed signal resulting from the interlaced spectral multiplexing of said N electrical signals ; a first diffracting system positioned on the path of said luminous beam ; an optical separating device positioned for receiving the luminous energy diffracted by said diffracting system ; said separating device supplying a filtered beam comprising selected portions of the diffracted luminous energy emerging from said first diffracting system ; a second diffracting system positioned for receiving said filtered beam ; and photoelectric means positioned for receiving the luminous rays emerging from said second diffracting system.
Claim 6
Dependent Claim
72 words
A spectral multiplexing apparatus as claimed in claim 1, wherein each of said N electro optical modulators comprises a transparent plate, electro mechanical transducer means coupled to said plate for exciting therein a deformation wave corresponding to one of said electrical signals, and optical phase contrast means associated to said plate for converting the refractive index changes induced by said wave into corresponding changes of the luminous amplitudes emerging from said modulator.
Claim 7
Dependent Claim
82 words
A spectral multiplexing apparatus as claimed in claim 1, wherein each of said N electro optical modulators comprises a transparent strip carrying a photochromic substance, means for translating said strip at constant speed, a writing source of light capable of modifying the optical absorption coefficient of said photochromic substance, an erasing source of light positioned for bleaching said substance and an electro optical modulating cell positioned for modulating a pencil of light emerging from said writing source and incident onto said strip.
Claim 8
Dependent Claim
29 words
A spectral multiplexing apparatus as claimed in claim 4, wherein said writing source is a source of ultra-violet light ; said erasing source being a source of infra-red radiation.
Claim 9
Dependent Claim
24 words
A spectral multiplexing apparatus as claimed in claim 1, wherein said N first diffracting systems are converging lenses positioned for focusing said N beams.
Claim 10
Dependent Claim
36 words
A spectral multiplexing apparatus as claimed in claim 1, wherein said second diffracting system comprises a lens for forming on the input face of said photoelectric means an image of the output face of said modulators.
Claim 11
Dependent Claim
27 words
A spectral multiplexing apparatus as claimed in claim 1, wherein said photoelectric means comprise a mask having a slit and a photoelectric transducer positioned behind said slit.
Claim 12
Dependent Claim
58 words
A spectral multiplexing apparatus as claimed in claim 1, wherein said optical interlacing device comprises a semi-transparent mirror and two optical filters having a plurality of parallel slOts ; said filters being positioned with respect to said mirror for forming an image of the slots of one of said filters interlaced with the slots of said other filter.
Claim 13
Dependent Claim
20 words
A spectral multiplexing apparatus as claimed in claim 9, wherein said slots have a constant width and are evenly spaced.
Claim 14
Dependent Claim
27 words
A spectral multiplexing apparatus as claimed in claim 9, wherein said slots have distinct widths and are spaced from each other according to a pseudo random law.
Claim 15
Dependent Claim
38 words
A spectral multiplexing apparatus as claimed in claim 9, wherein said slots have distinct widths ; the spacing between two successive slots being proportional to the distance of said two slots from the center slot of the array.
Claim 16
Dependent Claim
38 words
A spectral multiplexing apparatus as claimed in claim 1, wherein said optical interlacing device comprises a filter have a plurality of parallel slots located between reflecting strips and a semi-transparent mirror positioned obliquely with respect to said strips.
Claim 17
Dependent Claim
21 words
A spectral multiplexing apparatus as claimed in claim 13, wherein said reflecting strips are partially covered by a non reflecting coating.
Claim 18
Dependent Claim
67 words
A spectral demultiplexing apparatus as claimed in claim 2, wherein said electro optical modulator comprises a transparent plate, electro mechanical transducer means coupled to said plate for exciting therein a deformation wave corresponding to said multiplexed signal, and optical phase contrast means associated with said plate for converting the refractive index changes induced by said wave into corresponding changes of the luminous amplitudes emerging from said modulator.
Claim 19
Dependent Claim
81 words
A spectral demultiplexing apparatus as claimed in claim 2, wherein said electro optical modulator comprises a transparent loop carrying a photochromic substance, means for impressing to said loop a constant velocity translation, a writing source of light capable of increasing the optical absorption coefficient of said photochromic substance, an erasing source of light positioned for bleaching said substance and an electro optical modulating cell positioned for modulating a pencil of light emerging from said writing source and incident onto said loop.
Claim 20
Dependent Claim
29 words
A spectral demultiplexing apparatus as claimed in claim 16, wherein said writing source is a source of ultra-violet light ; said erasing source being a source of infra-red radiation.
Claim 21
Dependent Claim
23 words
A spectral demultiplexing apparatus as claimed in claim 2, wherein said first diffracting system is a converging lens positioned for focusing said beam.
Claim 22
Dependent Claim
36 words
A spectral demultiplexing apparatus as claimed in claim 2, wherein said second diffracting system comprises a lens for forming onto the input face of said photoelectric means an image of the output face of said modulator.
Claim 23
Dependent Claim
27 words
A spectral demultiplexing apparatus as claimed in claim 2, wherein said photoelectric means comprise a mask having a slit and a photoelectric transducer positioned behind said slit.
Claim 24
Dependent Claim
25 words
A spectral demultiplexing apparatus as claimed in claim 2, wherein said optical separating device comprises at least one filter having a plurality of parallel slots.
Claim 25
Dependent Claim
19 words
A spectral demultiplexing apparatus as claimed in claim 21, wherein said optical separating device further comprises a semi-reflecting mirror.
Claim 26
Dependent Claim
20 words
A spectral demultiplexing apparatus as claimed in claim 21, wherein said slots have a constant width and are evenly spaced.
Claim 27
Dependent Claim
27 words
A spectral demultiplexing apparatus as claimed in claim 21, wherein said slots have distinct widths and are spaced from each other according to a pseudo random law.
Claim 28
Dependent Claim
38 words
A spectral demultiplexing apparatus as claimed in claim 21, wherein said slots have distinct widths ; the spacing between two successive slots being proportional to the distance of said two slots from the center slot of the array.
Claim 29
Dependent Claim
22 words
A spectral demultiplexing apparatus as claimed in claim 21, wherein said filter comprise a plurality of reflecting strips interlaced with said slots.
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) | 1975-11-21 | 1976-05-22 | 1976-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-11-21 | 1980-05-22 | 1980-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-11-21 | 1984-05-22 | 1984-11-21 | $7700.00 | Window Closed / Lapsed |