US4794351A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical mixer for upconverting or downconverting an optical signal
Assignee: Nokia Bell Labs
•
Filing: 1986-09-29
•
Granted: 1988-12-27
•
Expires: 2006-09-29
Abstract
Abstract The present invention relates to an optical upconverting or downconverting gain or loss modulating mixer and a receiver for subcarrier optical communication systems using this mixer. The optical mixer can be formed, for example, from an optical amplifier including a semiconductor laser chip comprising a p-n junction with an active region channel formed along the junction. An optical signal received from the communication system is directed into one end of the channel, and a combination of a D-C bias signal and a local oscillator signal is concurrently impressed on the chip to gain-modulate the received optical signal and produce an upconverted or downconverted output signal. In the receiver, the upconverted or downconverted output signal from the gain-modulated optical amplifier is detected by a photodetector, amplified if necessary, filtered and then demodulated before transmission to the output utilization device. A loss modulator provides similar optical mixing but does not provide a gain to the output signal.
Inventors
- 👤 Thomas E. Darcie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 06:38
CPC Classifications
G; G02; G02F; G02F2/00; G02F2/002; H; H01; H01S; H01S5/00; H01S5/06; H01S5/0607; H01S5/0608; H04; H04B; H04B10/00; H04B10/60; H01S5/50
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
59 words
An optical mixer comprising: an optical modulator including an active channel region for receiving and propagating therealong a subcarrier modulated optical signal; and means for concurrently impressing a predetermined D-C bias signal and a predetermined local oscillator signal across the optical modulator for intensity modulating the received subcarrier optical signal to produce an upconverted or downconverted optical output signal.
Claim 2
Dependent Claim
59 words
An optical mixer comprising: an optical modulator including an active channel region for receiving and propagating therealong a subcarrier modulated optical signal; and means for concurrently impressing a predetermined D-C bias signal and a predetermined local oscillator signal across the optical modulator for intensity modulating the received subcarrier optical signal to produce an upconverted or downconverted optical output signal.
Claim 3
Dependent Claim
124 words
An optical mixer according to claim 1 wherein the optical modulator is a laser amplifier including a semiconductor laser comprising: a p-layer and an n-layer of semiconductor material forming a junction therebetween including an active channel region in one of the layers, the active channel region extending between a first and a second edge of the junction; and a first and a second conductive layer disposed both on a surface of the p-layer and the n-layer, respectively, opposite the junction, and overlapping the active channel region, the first and second conductive layers being connected to the impressing means for impressing the D-C bias and predetermined subcarrier signals across the active channel region to gain modulate an optical signal propagating in the active channel region.
Claim 4
Dependent Claim
152 words
An optical mixer according to claim 1 wherein the optical modulator is a loss modulator comprising: first optical waveguiding means for receiving the subcarrier modulated optical signal at a first end thereof and propagating the subcarrier modulated optical signal towards a second end thereof; second optical waveguiding means disposed adjacent the first optical waveguiding means for a predetermined length thereof; and the impressing means comprises at least one electrode disposed in proximity to the first and second waveguiding means, in the area where the two waveguiding means are adjacent each other, for causing a portion of the received subcarrier modulated optical signal propagating in the first optical waveguiding means to be switched into the second optical waveguiding means in accordance with the amplitude of the D-C bias signal and the predetermined subcarrier signal and produce the upconverted or downconverted optical output signal at the second end of the first optical waveguiding means.
Claim 5
Dependent Claim
62 words
An optical mixer according to claim 1, 2 or 3 wherein the subcarrier modulated signal received by the optical modulator comprises a plurality of subcarrier modulated signals disposed in separate frequency bands, and the predetermined local oscillator signal provided by the impressing means converts the frequency of a desired one of the plurality of subcarrier modulated signals to a predetermined frequency band.
Claim 6
Dependent Claim
95 words
An optical receiver comprising: an optical modulator including an active channel region for receiving and propagating therealong a subcarrier modulated optical signal received at an input to the optical receiver; means for concurrently impressing both a predetermined D-C bias signal and a predetermined local oscillator signal across the optical modulator for intensity modulating the received subcarrier optical signal to produce an upconverted or downconverted optical output signal at an output of the optical modulator; and a photodetector for converting the upconverted or downconverted optical output signal from the optical modulator into a corresponding electrical signal.
Claim 7
Dependent Claim
95 words
An optical receiver comprising: an optical modulator including an active channel region for receiving and propagating therealong a subcarrier modulated optical signal received at an input to the optical receiver; means for concurrently impressing both a predetermined D-C bias signal and a predetermined local oscillator signal across the optical modulator for intensity modulating the received subcarrier optical signal to produce an upconverted or downconverted optical output signal at an output of the optical modulator; and a photodetector for converting the upconverted or downconverted optical output signal from the optical modulator into a corresponding electrical signal.
Claim 8
Dependent Claim
132 words
An optical receiver according to claim 5 wherein the optical modulator is a laser amplifier including a semiconductor laser comprising: a p-layer and an n-layer of semiconductor material forming a junction therebetween including an active channel region in one of the layers, the active channel region extending between a first and a second edge of the junction; and a first and a second conductive layer disposed both (a) on a surface of the p-layer and the n-layer opposite the junction, respectively, and (b) overlapping the active channel region, the first and second conductive layers being connected to the impressing means for impressing the D-C bias and predetermined subcarrier signals across the active channel region to gain-modulate a subcarrier modulated optical signal received by the receiver and propagating in the active channel region.
Claim 9
Dependent Claim
153 words
An optical receiver according to claim 5 wherein the optical modulator is a loss modulator comprising: first optical waveguiding means for receiving the subcarrier modulated optical signal at a first end thereof and propagating the subcarrier modulated optical signal towards a second end thereof; and second optical waveguiding means disposed adjacent the first optical waveguiding means for a predetermined length thereof; and the impressing means comprises at least one electrode disposed in proximity to the first and second waveguiding means, in the area where the two waveguiding means are adjacent each other, for causing a portion of the received subcarrier modulated optical signal propagating in the first optical waveguiding means to be switched into the second optical waveguiding means in accordance with the amplitude of the D-C bias signal and the predetermined subcarrier signal and produce the upconverted or downconverted optical output signal at the second end of the first optical waveguiding means.
Claim 10
Dependent Claim
75 words
An optical receiver according to claim 5, 6 or 7 wherein the subcarrier modulated optical signal received at the input to the optical receiver comprises a plurality of subcarrier modulated signals disposed in separate frequency bands, the optical receiver further comprising: means for filtering the output signal from the photodetector for passing only a predetermined frequency band comprising an output signal including a desired one of from the plurality of amplified-downconverted received subcarrier modulated signals.
References Cited (Backward Citations)
US3301625A
Cited
US3295911A
Cited
US3309526A
Cited
US3842372A
Cited
US3724926A
Cited
US3806834A
Cited
US3860880A
Cited
US4012113A
Cited
US4317236A
Cited
US4349907A
Cited
US4545075A
Cited
US4468766A
Cited
US4546476A
Cited
US4706300A
Cited
US4723616A
Cited
US4507775A
Cited
US4554510A
Cited
US4503403A
Cited
EP0145972A1
Cited
GB2168561A
Cited
US4723317A
Cited
US4754452A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-12-27 | 1992-06-27 | 1992-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-12-27 | 1996-06-27 | 1996-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-12-27 | 2000-06-27 | 2000-12-27 | $7700.00 | Window Closed / Lapsed |