US3722982A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coherent optical processing method and system having improved signal-to-noise ratio utilizing polarizing filters
Assignee: Westinghouse Electric Corp
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Filing: 1971-10-26
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Granted: 1973-03-27
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Expires: 1991-10-26
Abstract
Abstract A coherent optical processing method and system for improving signal to noise ratio. A coherent optical beam which can be polarized or unpolarized is split into two component beams which are then polarized to two separate orthogonal states of polarization. Each component beam is operated upon to impart information thereto or sent through a transmission channel during which operation and transmission a small portion of each component beam is unavoidably scattered and depolarized. Each component beam is thereafter optically filtered with a polarizer aligned with the polarization state of each component beam, thereby removing approximately half of the depolarized noise portions of each component beam. The filtered component beams are then recombined, forming a polarized beam with a noise component depolarized with respect to the polarization beam. The combined polarized beam is again filtered in a polarizer aligned with the polarization state of the combined beam to reduce the depolarized noise portion again by about half. The resultant polarized beam has a signal to noise enhancement of about four by the inventive system.
Inventors
- 👤 G Brandt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:21
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/28; G02B27/283; G06; G06E; G06E3/00; G06E3/001
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
135 words
A method of optically processing a coherent polarized optical beam to enhance signal to noise ratio, said method comprising: separating said coherent polarized beam into at least two component beams whose polarization states are angularly disposed with respect to each other; processing each of said component beams and thereby unavoidably scattering and depolarizing a portion of each of said component beams; optically filtering each of said component beams with polarizers aligned with the polarization states of said component beams to filter said scattered and depolarized portions of each of said component beams; recombining said filtered component beams into a coherent polarized beam having a depolarized noise portion; and optically filtering said recombinEd polarized beam with a polarizer aligned with the polarization state of said recombined polarized beam to further filter and depolarize said noise portion.
Claim 2
Independent Claim
135 words
A method of optically processing a coherent polarized optical beam to enhance signal to noise ratio, said method comprising: separating said coherent polarized beam into at least two component beams whose polarization states are angularly disposed with respect to each other; processing each of said component beams and thereby unavoidably scattering and depolarizing a portion of each of said component beams; optically filtering each of said component beams with polarizers aligned with the polarization states of said component beams to filter said scattered and depolarized portions of each of said component beams; recombining said filtered component beams into a coherent polarized beam having a depolarized noise portion; and optically filtering said recombinEd polarized beam with a polarizer aligned with the polarization state of said recombined polarized beam to further filter and depolarize said noise portion.
Claim 3
Dependent Claim
39 words
A method of optically processing a coherent polarized optical beam according to claim 1 wherein the polarization state of each of said component beams is angularly disposed with respect to the polarization state of said coherent polarized optical beam.
Claim 4
Dependent Claim
28 words
A method of optically processing a coherent polarized optical beam according to claim 2 wherein the angle between the polarization states of said component beams is about 90*.
Claim 5
Dependent Claim
36 words
A method of optically processing a coherent polarized optical beam according to claim 1 wherein equal angles are made between the polarization state of each component beam and the polarization state of said coherent polarized beam.
Claim 6
Dependent Claim
29 words
A method of optically processing a coherent polarized optical beam according to claim 1 wherein said processing step includes modulating each of said component beams in an identical manner.
Claim 7
Dependent Claim
30 words
A method of optically processing a coherent polarized optical beam according to claim 1 wherein said processing step includes transmitting each of said beam components through an identical transmission channel.
Claim 8
Independent Claim
148 words
A method of optically processing a coherent optical beam to enhance signal to noise ratio, said method comprising: separating said optical beam into at least two component beams; polarizing each of said beams so that the polarization state of one of said component beams is angularly disposed with respect to the other; processing each of said component beams and thereby unavoidably scattering and depolarizing a portion of each of said component beams; optically filtering each of said component beams with a polarizer aligned with the polarization state of each of said component beams to filter said scattered and depolarized portions of each of said component beams; recombining said filtered component beams into a coherent polarized beam having a depolarized noise portion; and optically filtering said recombined polarized beam with a polarizer aligned with the polarization state of said recombined polarized beam to further filter said depolarized noise portion.
Claim 9
Independent Claim
148 words
A method of optically processing a coherent optical beam to enhance signal to noise ratio, said method comprising: separating said optical beam into at least two component beams; polarizing each of said beams so that the polarization state of one of said component beams is angularly disposed with respect to the other; processing each of said component beams and thereby unavoidably scattering and depolarizing a portion of each of said component beams; optically filtering each of said component beams with a polarizer aligned with the polarization state of each of said component beams to filter said scattered and depolarized portions of each of said component beams; recombining said filtered component beams into a coherent polarized beam having a depolarized noise portion; and optically filtering said recombined polarized beam with a polarizer aligned with the polarization state of said recombined polarized beam to further filter said depolarized noise portion.
Claim 10
Independent Claim
149 words
A system for processing a coherent optical beam comprising: means for separating an optical beam into two component beams having separate states of polarization; means for processing said component beams and thereby unavoidably scattering and depolarizing a portion of each of said component beams; first polarizing means for receiving said two component beams and respectively aligned with the polarization state of each thereof for passing said component beams and optically filtering said depolarized portions thereof; means optically associated with said first polarizing means for recombining said filtered component beams, and producing a coherent polarized beam with a depolarized noise portion thereof; and second polarization means optically associated with said recombining means and aligned with the polarization state of said combined beam to optically filter said depolarized portion of said recombined beam, whereby the signal to noise ratio of said optical beam is enhanced by a factor of about four.
Claim 11
Independent Claim
149 words
A system for processing a coherent optical beam comprising: means for separating an optical beam into two component beams having separate states of polarization; means for processing said component beams and thereby unavoidably scattering and depolarizing a portion of each of said component beams; first polarizing means for receiving said two component beams and respectively aligned with the polarization state of each thereof for passing said component beams and optically filtering said depolarized portions thereof; means optically associated with said first polarizing means for recombining said filtered component beams, and producing a coherent polarized beam with a depolarized noise portion thereof; and second polarization means optically associated with said recombining means and aligned with the polarization state of said combined beam to optically filter said depolarized portion of said recombined beam, whereby the signal to noise ratio of said optical beam is enhanced by a factor of about four.
Claim 12
Dependent Claim
18 words
A system for processing a coherent optical beam according to claim 8 wherein said optical beam is polarized.
Claim 13
Dependent Claim
19 words
A system for processing a coherent optical beam according to claim 9 wherein said processing means includes a modulator.
Claim 14
Dependent Claim
21 words
A system for processing a coherent optical beam according to claim 9 wherein said processing means includes an optical transmission means.
Claim 15
Dependent Claim
27 words
A system for processing a coherent optical beam according to claim 9 wherein said orthogonal states of polarization are disposed substantially 90* with respect to each other.
References Cited (Backward Citations)
US3465156A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |