Patent US4225239A successfully refreshed from Google Patents.
US4225239A
Expired / Lapsed
US
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Magneto-optic bias of ring laser using reflective magneto-optic element at near-grazing incidence
Assignee: United States Department of the Navy
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Filing: 1979-07-05
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Granted: 1980-09-30
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Expires: 1999-07-05
Abstract
Abstract A method of introducing magneto-optic bias into a ring laser permitting itsse as a gyroscope. A Kerr reflective mirror is positioned in one leg of a triangle between reflectors at two vertices so that radiation from a reflector at one of the vertices is reflected at the maximum practical angle of incidence to a reflector at the adjacent vertex. By incorporating the reflective magneto-optic element at near-grazing incidence, full advantage is taken of the dependence of the magneto-optical properties upon angle of incidence.
Inventors
- 👤 Gary A. Prinz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:03
CPC Classifications
G; G01; G01C; G01C19/00; G01C19/58; G01C19/64; G01C19/66; G01C19/68; H; H01; H01S; H01S3/00; H01S3/05; H01S3/08; H01S3/081; H01S3/083
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
50 words
In an improved ring laser including, in combination, means for radiating and reflecting clockwise and counterclockwise laser beams around said ring laser for biasing said beams, the improvement comprising: a magneto-optic mirror element placed between two corner, beam-reflecting surfaces so that the beams impinge on said element at near-grazing incidence.
Claim 2
Dependent Claim
50 words
In an improved ring laser including, in combination, means for radiating and reflecting clockwise and counterclockwise laser beams around said ring laser for biasing said beams, the improvement comprising: a magneto-optic mirror element placed between two corner, beam-reflecting surfaces so that the beams impinge on said element at near-grazing incidence.
Claim 3
Dependent Claim
20 words
The improvement in a ring laser as claimed in claim 1 wherein: said ring laser is formed as a triangle.
Claim 4
Dependent Claim
46 words
The improvement in a ring laser as claimed in claim 2 wherein: said magneto-optic mirror element includes a reflective film surface selected from the group consisting of Fe, Ni, Co, Ni 0 .75 Fe 0 .25, and Ni 0 .68 Fe 0 .32 on a subtrate.
Claim 5
Dependent Claim
28 words
The improvement in a ring laser as claimed in claim 2 wherein: said magneto-optic mirror element includes a reflective film surface of Fe on a SiO 2 substrate.
Claim 6
Dependent Claim
28 words
The improvement in a ring laser as claimed in claim 4 wherein: said film of Fe has a thickness of from about 200 A to about 800 A.
Claim 7
Dependent Claim
36 words
The improvement in a ring laser as claimed in claim 5 wherein: said film of Fe is aligned in said magneto-optic mirror element such that the net magnetization is directed along the easy-axis of said film.
Claim 8
Dependent Claim
26 words
The improvement in a ring laser as claimed in claim 1 wherein: the grazing angle of said beams is from 3 degrees to about 25 degrees.
References Cited (Backward Citations)
US3927946A
Cited
US3851973A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-09-30 | 1984-03-31 | 1984-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-30 | 1988-03-31 | 1988-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-30 | 1992-03-31 | 1992-09-30 | $7700.00 | Window Closed / Lapsed |