Patent US3770339A successfully refreshed from Google Patents.
US3770339A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Switch for fiber-optic transmission systems
Assignee: AT&T Inc
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Filing: 1972-12-06
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Granted: 1973-11-06
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Expires: 1992-12-06
Abstract
Abstract An optical switch for fiber-optic light guides utilizes an electrically induced change in the index of refraction of the switch material to produce the switching effect. Electrode rings are spaced along a cylindrical member of electro-optic switch material, which is placed between two sections of a fiber-optic light guide. When a voltage is applied between the electrodes, an electric field is produced in the switch material causing a change in the index of refraction and the creation of a light guide through the switch material. Removal of the voltage will destroy the guide in the switch material, thereby blocking transmission.
Inventors
- 👤 V Ramaswamy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:03
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/50; G; G02; G02F; G02F1/00; G02F1/01; G02F1/03; G02F1/035
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
124 words
An electro-optic switch for modulating light traveling in a fiber-optic light guide comprising: a member of electro-optic material located between segments of said fiber-optic light guide, said member of electro-optic material being oriented so that its optic axis is parallel with the axis of said fiber-optic light guide; and means for creating a variation in the index of refraction of said member of electro-optic material from a maximum along the axis of said fiber-optic light guide to a minimum near the surface of said member of electro-optic material, comprising a first electrode around one end of said member of electro-optic material, a second electrode around the other end of said member of electro-optic material and means for applying a voltage difference between said electrodes.
Claim 2
Dependent Claim
124 words
An electro-optic switch for modulating light traveling in a fiber-optic light guide comprising: a member of electro-optic material located between segments of said fiber-optic light guide, said member of electro-optic material being oriented so that its optic axis is parallel with the axis of said fiber-optic light guide; and means for creating a variation in the index of refraction of said member of electro-optic material from a maximum along the axis of said fiber-optic light guide to a minimum near the surface of said member of electro-optic material, comprising a first electrode around one end of said member of electro-optic material, a second electrode around the other end of said member of electro-optic material and means for applying a voltage difference between said electrodes.
Claim 3
Dependent Claim
19 words
An electro-optic switch as claimed in claim 1 wherein said member of electro-optic material consists of lithium niobate (LiNbO3).
Claim 4
Dependent Claim
19 words
An electro-optic switch as claimed in claim 1 wherein said member of electro-optic material consists of lithium tantalate (LiTaO3).
Claim 5
Dependent Claim
34 words
An electro-optic switch as claimed in claim 1 further including a dielectric material surrounding said switch, said dielectric material having an index of refraction higher than the index of refraction of said switch material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-11-05 | 1977-05-07 | 1977-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-05 | 1981-05-07 | 1981-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-05 | 1985-05-07 | 1985-11-06 | $7700.00 | Window Closed / Lapsed |