Patent US4893352A successfully refreshed from Google Patents.
US4893352A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical transmitter of modulated signals
Assignee: Massachusetts Institute of Technology
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Filing: 1987-06-30
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Granted: 1990-01-09
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Expires: 2007-06-30
Abstract
Abstract Orthogonal optical signals on a common waveguide are obtained by power splitting a light signal into a split waveguide, modulating at least one of the split signals and recombining the signals. The orthogonal signals may be obtained by separating the signals in frequency or by quadrature encoding. Frequency translation may be obtained by continuously varying an applied voltage to vary the dielectric constant of a leg of the split waveguide. One of the signals may also be frequency, phase or amplitude modulated. This split waveguide may serve as the frequency shifter and modulator in a three-frequency heterodyne system.
Inventors
- 👤 David Welford
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:44
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/50; H04B10/501; H04B10/503; H04B10/505; H04B10/5057; H04B10/50577
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
77 words
An optical waveguide modulator comprising: an input waveguide for carrying an input optical signal; an optical waveguide splitter for splitting the power of the input optical signal into plural signals in plural waveguides; modulator means for modulating at least one of the plural signals such that at least one of the plural signals has negligible energy in frequency ranges of all other plural signals; and an optical combiner for combining the signals into an output optical waveguide.
Claim 2
Dependent Claim
77 words
An optical waveguide modulator comprising: an input waveguide for carrying an input optical signal; an optical waveguide splitter for splitting the power of the input optical signal into plural signals in plural waveguides; modulator means for modulating at least one of the plural signals such that at least one of the plural signals has negligible energy in frequency ranges of all other plural signals; and an optical combiner for combining the signals into an output optical waveguide.
Claim 3
Dependent Claim
35 words
An optical waveguide modulator as claimed in claim 1 wherein the waveguides are diffused dielectric waveguides and the modulator means comprises means for applying a voltage signal to at least one of the plural waveguides.
Claim 4
Dependent Claim
24 words
An optical waveguide modulator as claimed in claim 1 wherein the modulator means comprises means for generating a saw-toothed function in synchronization with data.
Claim 5
Dependent Claim
32 words
An optical waveguide modulator as claimed in claim 3 wherein the modulator means includes means for applying a bilevel digital signal to one of the plural waveguides in response to the data.
Claim 6
Dependent Claim
23 words
An optical waveguide modulator as claimed in claim 1 wherein the modulator means supplies a sinusoidal signal to one of the plural waveguides.
Claim 7
Dependent Claim
31 words
An optical waveguide modulator as claimed in claim 5 wherein the modulator means includes means for applying a bilevel digital signal to one of the plural waveguides in response to data.
Claim 8
Dependent Claim
31 words
An optical waveguide modulator as claimed in claim 1 herein the modulator means includes means for applying a bilevel digital signal to one of the plural waveguides in response to data.
Claim 9
Dependent Claim
25 words
An optical waveguide modulator as claimed in claim 1 wherein the modulator means further comprises a split waveguide interferometer in one of the plural waveguides.
Claim 10
Dependent Claim
17 words
An optical waveguide modulator as claimed in claim 1 wherein the data is a sensed physical parameter.
Claim 11
Dependent Claim
29 words
An optical waveguide modulator as claimed in claim 1 further comprising means for obtaining feedback from the combined signals and for processing the feedback to control the modulator means.
Claim 12
Dependent Claim
104 words
An optical modulator comprising: a waveguide power splitter for splitting an input optical signal having an input frequency range from an input waveguide into plural signals in plural waveguides; modulator means for generating a signal in one of the plural waveguides which is displaced in frequency relative to a signal in another of the waveguides and which has negligible energy in the input frequency range and for modulating the signal in one of the plural waveguides with data; and a waveguide power combiner for combining plural signals from the plural waveguides, including the frequency displaced signal and data modulated signal, into a single waveguide.
Claim 13
Dependent Claim
104 words
An optical modulator comprising: a waveguide power splitter for splitting an input optical signal having an input frequency range from an input waveguide into plural signals in plural waveguides; modulator means for generating a signal in one of the plural waveguides which is displaced in frequency relative to a signal in another of the waveguides and which has negligible energy in the input frequency range and for modulating the signal in one of the plural waveguides with data; and a waveguide power combiner for combining plural signals from the plural waveguides, including the frequency displaced signal and data modulated signal, into a single waveguide.
Claim 14
Dependent Claim
35 words
An optical waveguide modulator as claimed in claim 11 wherein the waveguides are diffused dielectric waveguides and the modulator means comprises means for applying a voltage signal to at least one of the plural waveguides.
Claim 15
Dependent Claim
29 words
An optical waveguide modulator as claimed in claim 11 wherein separate ones of the plural signals in separate legs of the device are frequency displaced and modulated with data.
Claim 16
Dependent Claim
30 words
An optical waveguide modulator as claimed in claim 11 wherein the modulator means comprises means for generating a sawtooth function in synchronization with data with which a signal is modulated.
Claim 17
Dependent Claim
23 words
An optical waveguide modulator as claimed in claim 11 wherein the modulator means supplies a sinusoidal signal to one of the plural waveguides.
Claim 18
Dependent Claim
27 words
An optical waveguide modulator as claimed in claim 11 wherein the modulator means includes means for applying a bilevel digital signal to one of the plural waveguides.
Claim 19
Dependent Claim
24 words
An optical waveguide modulator as claimed in claim 11 wherein the modulator means comprises a split waveguide interferometer in one of the plural waveguides.
Claim 20
Dependent Claim
25 words
An optical waveguide modulator as claimed in claim 11 wherein the modulator means frequency modulates a signal in one of the plural waveguides with data.
Claim 21
Dependent Claim
17 words
An optical waveguide modulator as claimed in claim 11 wherein the data is a sensed physical parameter.
Claim 22
Dependent Claim
30 words
An optical waveguide modulator as claimed in claim 11 further comprising means for obtaining feedback from the combined orthogonal signals and for processing the feedback to control the modulator means.
Claim 23
Dependent Claim
113 words
A three-frequency heterodyne communication system comprising: a waveguide power splitter for splitting an optical signal from a waveguide into plural signals in plural waveguides; modulator means for generating a signal in one of the plural waveguides which is displaced in frequency relative to a signal in another of the waveguides and which has negligible energy in the input frequency range and for modulating the signal in one of the plural waveguides with data; and a waveguide power combiner for combining plural signals from the plural waveguides, including the frequency displaced signal and the data modulated signal, into a single waveguide; and three-frequency heterodyne receiver means for recovering data from the combined plural signals.
Claim 24
Dependent Claim
113 words
A three-frequency heterodyne communication system comprising: a waveguide power splitter for splitting an optical signal from a waveguide into plural signals in plural waveguides; modulator means for generating a signal in one of the plural waveguides which is displaced in frequency relative to a signal in another of the waveguides and which has negligible energy in the input frequency range and for modulating the signal in one of the plural waveguides with data; and a waveguide power combiner for combining plural signals from the plural waveguides, including the frequency displaced signal and the data modulated signal, into a single waveguide; and three-frequency heterodyne receiver means for recovering data from the combined plural signals.
Claim 25
Dependent Claim
36 words
A three-frequency heterodyne communication system as claimed in claim 21 wherein the waveguides are diffused dielectric waveguides and the modulator means comprises means for applying a voltage signal to at least one of the plural waveguides.
Claim 26
Dependent Claim
26 words
A three-frequency heterodyne communication system as claimed in claim 21 wherein the modulator means comprises means for generating a sawtooth function in synchronization with the data.
Claim 27
Dependent Claim
24 words
A three-frequency heterodyne communication system as claimed in claim 21 wherein the modulator means applies a sinusoidal signal to one of the plural waveguides.
Claim 28
Dependent Claim
28 words
A three-frequency heterodyne communication system as claimed in claim 21 wherein the modulator means includes means for applying a bilevel digital signal to one of the plural waveguides.
Claim 29
Dependent Claim
25 words
A three-frequency heterodyne communication system as claimed in claim 21 wherein the modulator means comprises a split waveguide interferometer in one of the plural waveguides.
Claim 30
Independent Claim
97 words
A method of modulating optical signals which are frequency shifted relative to each other comprising: power splitting a light signal into plural waveguides; varying the propagation delay through one of the plural waveguides to cause a frequency redistribution of the light in that waveguide relative to the light in another of the plural waveguides such that the light in that waveguide has negligible energy in the frequency range of light in the other waveguide; modulating the light in one of the waveguides with data; and combining the signals from the plural waveguides in a waveguide power combiner.
Claim 31
Independent Claim
97 words
A method of modulating optical signals which are frequency shifted relative to each other comprising: power splitting a light signal into plural waveguides; varying the propagation delay through one of the plural waveguides to cause a frequency redistribution of the light in that waveguide relative to the light in another of the plural waveguides such that the light in that waveguide has negligible energy in the frequency range of light in the other waveguide; modulating the light in one of the waveguides with data; and combining the signals from the plural waveguides in a waveguide power combiner.
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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) | 1993-01-08 | 1993-07-10 | 1994-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-08 | 1997-07-10 | 1998-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-08 | 2001-07-10 | 2002-01-09 | $7700.00 | Window Closed / Lapsed |