US4518934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical bistable device
Assignee: Nokia Bell Labs
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Filing: 1982-02-16
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Granted: 1985-05-21
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Expires: 2002-02-16
Abstract
Abstract An optically integrated bistable device includes a semiconductor junction Fabry-Perot interferometer cavity and a pair of electrodes for applying a reverse-bias voltage to the junction to increase its light absorption. A capacitor is connected between one electrode and ground for eliminating spurious high-speed signals. A resistor is connected in series with the voltage source between the electrodes to decrease the back-bias in response to photocurrent for a negative feedback.
Inventors
- 👤 Thirumalai N. C. Venkatesan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:01
CPC Classifications
G; G02; G02F; G02F3/00; G02F3/02; G02F3/024; G02F1/00; G02F1/01; G02F1/015; G02F1/025; G02F1/21; G02F1/218; G02F1/0155; G02F1/0157
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
153 words
An optical bistable device of the type comprising: means defining a Fabry-Perot interferometer cavity with an input face parallel to and spaced from an output face: an optical absorbing medium within said cavity; and means including a pair of electrodes for generating an electric field within said medium; said device being characterized by: at least two contiguous regions of different conductivity type in said medium and oriented between said electrodes so that a reverse-bias electric field results when a driving voltage is applied to said electrodes by a driving voltage source; and resistance means connected in series between one of said electrodes and said driving voltage source for generating a back-voltage in response to photo-generated current flow between said electrodes, whereby photo-generated current which is generated between said electrodes results in a reduction of the electric field within said medium to provide negative feedback response to a light signal incident on said medium.
Claim 2
Dependent Claim
153 words
An optical bistable device of the type comprising: means defining a Fabry-Perot interferometer cavity with an input face parallel to and spaced from an output face: an optical absorbing medium within said cavity; and means including a pair of electrodes for generating an electric field within said medium; said device being characterized by: at least two contiguous regions of different conductivity type in said medium and oriented between said electrodes so that a reverse-bias electric field results when a driving voltage is applied to said electrodes by a driving voltage source; and resistance means connected in series between one of said electrodes and said driving voltage source for generating a back-voltage in response to photo-generated current flow between said electrodes, whereby photo-generated current which is generated between said electrodes results in a reduction of the electric field within said medium to provide negative feedback response to a light signal incident on said medium.
Claim 3
Dependent Claim
31 words
The device defined in claim 1 and comprising a capacitor connected between one of said electrodes and a reference potential for reducing the response of said device to spurious, high-speed signals.
Claim 4
Dependent Claim
18 words
The device defined in claim 2 wherein said medium is a semiconductor material having a direct energy bandgap.
Claim 5
Dependent Claim
23 words
The device defined in claim 3 comprising reflective coatings on said input and output faces for increasing the finesse of said Fabry-Perot cavity.
Claim 6
Dependent Claim
25 words
The device defined in claim 4 wherein said medium is chosen from the group consisting of GaAs, GaAlAs, InGaAsP, InSb, InGaSb, InP, InAs, and GaSb.
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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) | 1988-05-20 | 1988-11-19 | 1989-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-20 | 1992-11-19 | 1993-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-20 | 1996-11-19 | 1997-05-21 | $7700.00 | Window Closed / Lapsed |