Patent US4733938A successfully refreshed from Google Patents.
US4733938A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magneto-optic rotator
Assignee: Leland Stanford Junior University
•
Filing: 1986-02-13
•
Granted: 1988-03-29
•
Expires: 2006-02-13
Abstract
Abstract A single, continuous strand of fiber optic material is wrapped about a mandrel to form oval-shaped loops having parallel sides and curved ends. A magnet is positioned so that its B-field is substantially parallel to the straight portions of the loops. As light propagates through these straight portions of the loops, its direction of polarization is rotated in accordance with the Faraday effect. The curved portions are formed to create sufficient linear birefrigence to provide a phase difference of 180 degrees between light in the two orthogonal polarization modes of the fiber. This advantageously causes the Faraday rotations in each of the straight portions to add, rather than cancel. The magneto-optic rotator of the present invention is useful in a variety of applications such as an optical isolator, a modulator, and a magnetometer.
Inventors
- 👤 Herve C. LeFevre
- 👤 Ralph A. Bergh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:55
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/09; G01; G01R; G01R33/00; G01R33/02; G01R33/032; G01R33/0322
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
190 words
A magneto-optic rotator, comprising: a series of portions of optical fiber, said fiber portions oriented to cause Faraday rotation of a lightwave propagating therethrough upon exposure to a magnetic field; and means for optically interconnecting said fiber portions to provide a continuous optical path for propagation of said lightwave serially through each of said fiber portions, said interconnecting means reversing the direction of propagation of said lightwave from the perspective of a fixed observer as it serially propagates from one of said series of fiber portions to the next adjacent one of said series of fiber portions such that the propagation direction of said lightwave reverses relative to the direction of said magnetic field to cause said Faraday rotation to be in one direction for said one of said series of fiber portions and in the opposite direction for said next adjacent one of said series of fiber portions from the perspective of said lightwave, said interconnecting means including means for transforming the polarization of said lightwave including an amount sufficient to cause the Faraday rotations in said fiber portions to be additive from the perspective of a fixed observer.
Claim 2
Dependent Claim
190 words
A magneto-optic rotator, comprising: a series of portions of optical fiber, said fiber portions oriented to cause Faraday rotation of a lightwave propagating therethrough upon exposure to a magnetic field; and means for optically interconnecting said fiber portions to provide a continuous optical path for propagation of said lightwave serially through each of said fiber portions, said interconnecting means reversing the direction of propagation of said lightwave from the perspective of a fixed observer as it serially propagates from one of said series of fiber portions to the next adjacent one of said series of fiber portions such that the propagation direction of said lightwave reverses relative to the direction of said magnetic field to cause said Faraday rotation to be in one direction for said one of said series of fiber portions and in the opposite direction for said next adjacent one of said series of fiber portions from the perspective of said lightwave, said interconnecting means including means for transforming the polarization of said lightwave including an amount sufficient to cause the Faraday rotations in said fiber portions to be additive from the perspective of a fixed observer.
Claim 3
Dependent Claim
24 words
A magneto-optic rotator, as defined by claim 1, wherein said interconnecting means comprises a curved portion of optical fiber, integral with said fiber portions.
References Cited (Backward Citations)
US3756689A
Cited
US3756690A
Cited
US4255018A
Cited
US4298245A
Cited
US4299490A
Cited
DE2855337A1
Cited
US4372685A
Cited
EP0044572A1
Cited
US4389090A
Cited
US4410275A
Cited
US4450406A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-29 | 1991-09-28 | 1992-03-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-29 | 1995-09-28 | 1996-03-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-29 | 1999-09-28 | 2000-03-29 | $7700.00 | Window Closed / Lapsed |