Patent US2833801A successfully refreshed from Google Patents.
Patent US4769853A successfully refreshed from Google Patents.
US4769853A
Expired / Lapsed
US
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High dynamic range fiber optical link
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1987-10-23
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Granted: 1988-09-06
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Expires: 2007-10-23
Abstract
Abstract Apparatus, and a corresponding method for its use, for modulating an optical carrier signal with a radio-frequency signal and providing a desirably high dynamic range. An optical signal source is split into a carrier signal and a reference signal, ideally with an optical star coupler, and the carrier signal is phase-modulated with the radio-frequency signal by means of a Pockels cell, producing a phase-modulated signal devoid of even-harmonic distortion, and containing only relatively small odd-harmonic components. In the preferred embodiment of the invention, the phase-modulated signal has its carrier signal suppressed. Then the resulting double-side-band suppressed-carrier signal is combined with the reference signal, preferably with another optical star coupler, to produce the desired modulated optical signal with high dynamic range.
Inventors
- 👤 Francis E. Goodwin
- 👤 Gordon R. Orme
- 👤 Peter G. Petrelis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 19:47
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/50
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
111 words
A fiber optical communications link, comprising: a source of monochromatic, coherent, optical radiation; signal dividing means, for producing a reference signal and a carrier signal; electro-optical phase modulation means, for modulating the carrier signal with a radio-frequency signal to produce a phase-modulated double-sideband signal; means for removing the carrier signal from the phase-modulated double-sideband signal, to produce a phase-modulated double-sideband suppressed-carrier signal; means for adjusting the plane of polarization of the phase-modulated double-sideband suppressed-carrier signal to match that of the reference signal; and signal combining means, for combining the phase-modulated polarization-adjusted double-sideband suppressed-carrier signal with the reference signal, to produce as an output a modulated optical signal with high dynamic range.
Claim 2
Dependent Claim
111 words
A fiber optical communications link, comprising: a source of monochromatic, coherent, optical radiation; signal dividing means, for producing a reference signal and a carrier signal; electro-optical phase modulation means, for modulating the carrier signal with a radio-frequency signal to produce a phase-modulated double-sideband signal; means for removing the carrier signal from the phase-modulated double-sideband signal, to produce a phase-modulated double-sideband suppressed-carrier signal; means for adjusting the plane of polarization of the phase-modulated double-sideband suppressed-carrier signal to match that of the reference signal; and signal combining means, for combining the phase-modulated polarization-adjusted double-sideband suppressed-carrier signal with the reference signal, to produce as an output a modulated optical signal with high dynamic range.
Claim 3
Dependent Claim
19 words
A fiber optical communication link as set forth in claim 1, wherein: the phase-modulation means includes a Pockels cell.
Claim 4
Dependent Claim
22 words
A fiber optical communication link as set forth in claim 1, wherein: the means for removing the carrier signal includes a polarizer.
Claim 5
Dependent Claim
24 words
A fiber optical communication link as set forth in claim 1, wherein: the means for adjusting the plane of polarization includes a half-wave plate.
Claim 6
Independent Claim
107 words
A method for modulating an optical carrier signal, comprising the steps of: dividing a coherent source of light into two approximately equal portions, referred to as a reference signal and a carrier signal; modulating the phase of the carrier signal with a radio-frequency signal; removing the carrier signal from the phase-modulated signal to provide a phase-modulated double-sideband suppressed-carrier signal; adjusting the plane of polarization of the phase-modulated double-sideband suppressed-carrier signal to match that of the reference signal; combining the reference signal and the phasemodulated polarization-adjusted double-sideband suppressed-carrier signal; and providing, as a result of the combining step, a modulated optical signal that has a high dynamic range.
Claim 7
Independent Claim
107 words
A method for modulating an optical carrier signal, comprising the steps of: dividing a coherent source of light into two approximately equal portions, referred to as a reference signal and a carrier signal; modulating the phase of the carrier signal with a radio-frequency signal; removing the carrier signal from the phase-modulated signal to provide a phase-modulated double-sideband suppressed-carrier signal; adjusting the plane of polarization of the phase-modulated double-sideband suppressed-carrier signal to match that of the reference signal; combining the reference signal and the phasemodulated polarization-adjusted double-sideband suppressed-carrier signal; and providing, as a result of the combining step, a modulated optical signal that has a high dynamic range.
Claim 8
Dependent Claim
109 words
A fiber optical communications link, comprising: a source of monochromatic, electromagnetic radiation; signal dividing means, for producing a reference signal and a carrier signal; electro-optical phase modulation means, for modulating the carrier signal with an information signal to produce a phase-modulated double-sideband signal; means for removing the carrier signal from the phase-modulated double-sideband signal, to produce a phase-modulated double-sideband suppressed-carrier signal; means for adjusting the plane of polarization of the phase-modulated double-sideband suppressed-carrier signal to match that of the reference signal; signal combining means, for combining the phase-modulated, polarization-adjusted double-sideband suppressed-carrier signal with the reference signal, to produce as an output a modulated electromagnetic signal with high dynamic range.
Claim 9
Dependent Claim
109 words
A fiber optical communications link, comprising: a source of monochromatic, electromagnetic radiation; signal dividing means, for producing a reference signal and a carrier signal; electro-optical phase modulation means, for modulating the carrier signal with an information signal to produce a phase-modulated double-sideband signal; means for removing the carrier signal from the phase-modulated double-sideband signal, to produce a phase-modulated double-sideband suppressed-carrier signal; means for adjusting the plane of polarization of the phase-modulated double-sideband suppressed-carrier signal to match that of the reference signal; signal combining means, for combining the phase-modulated, polarization-adjusted double-sideband suppressed-carrier signal with the reference signal, to produce as an output a modulated electromagnetic signal with high dynamic range.
Claim 10
Independent Claim
121 words
A method for modulating an optical carrier signal, comprising the steps of: dividing a source of optical radiation which is not limited to the visible spectrum, into two portions, referred to as a reference signal and a carrier signal; electro-optically modulating the phase of the carrier signal with an information signal to produce a phase-modulated double-sideband signal; removing the carrier signal from the phase-modulated double-sideband signal to provide a phase-modulated double-sideband suppressed-carrier signal; adjusting the plane of polarization of the phase-modulated double-sideband suppressed-carrier signal to match that of the reference signal; combining the reference signal and the phasemodulated polarization-adjusted double-sideband suppressed-carrier signal; and providing, as a result of the combining step, a modulated electromagnetic signal that has a high dynamic range.
Claim 11
Independent Claim
121 words
A method for modulating an optical carrier signal, comprising the steps of: dividing a source of optical radiation which is not limited to the visible spectrum, into two portions, referred to as a reference signal and a carrier signal; electro-optically modulating the phase of the carrier signal with an information signal to produce a phase-modulated double-sideband signal; removing the carrier signal from the phase-modulated double-sideband signal to provide a phase-modulated double-sideband suppressed-carrier signal; adjusting the plane of polarization of the phase-modulated double-sideband suppressed-carrier signal to match that of the reference signal; combining the reference signal and the phasemodulated polarization-adjusted double-sideband suppressed-carrier signal; and providing, as a result of the combining step, a modulated electromagnetic signal that has a high dynamic range.
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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) | 1991-09-06 | 1992-03-07 | 1992-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-09-06 | 1996-03-07 | 1996-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-09-06 | 2000-03-07 | 2000-09-06 | $7700.00 | Window Closed / Lapsed |