US4856878A
Expired / Lapsed
US
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Magnetic configuration for Faraday rotators
Assignee: Optics for Research
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Filing: 1987-12-04
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Granted: 1989-08-15
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Expires: 2007-12-04
Abstract
Abstract A Faraday rotator having an optical element and a donut magnet of length 1.0L for generating a magnetic field along the optical axis of the optical element in order to rotate a plane of polarization of polarized light. At each end of the donut magnet of length 1.0L is a tuning magent of a length from about 0.4L to about 0.7L, with each of said tuning magnets generating a magnetic field in a direction opposite to that of the donut magnet.
Inventors
- 👤 Donald K. Wilson
- 👤 Allan Heiney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:13
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/09; G02F1/093
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
127 words
A Faraday rotator comprising: an optical element having an optical axis, said optical element being made of a light transmitting material; a first magnet for generating a magnetic field along the optical axis of said optical element, said magnet having a front end and a rear end, said magnetic field being generated in one direction and said first magnet having a specified length 1.0L; and a pair of tuning magnets, each tuning magnet being located at a front end or a rear end of said first magnet, each tuning magnet generating a magnetic field in a direction opposite to the direction of the magnetic field being generated by said first magnet, and the total combined length of said tuning magnets being from about 0.8L to about 1.4L.
Claim 2
Dependent Claim
127 words
A Faraday rotator comprising: an optical element having an optical axis, said optical element being made of a light transmitting material; a first magnet for generating a magnetic field along the optical axis of said optical element, said magnet having a front end and a rear end, said magnetic field being generated in one direction and said first magnet having a specified length 1.0L; and a pair of tuning magnets, each tuning magnet being located at a front end or a rear end of said first magnet, each tuning magnet generating a magnetic field in a direction opposite to the direction of the magnetic field being generated by said first magnet, and the total combined length of said tuning magnets being from about 0.8L to about 1.4L.
Claim 3
Dependent Claim
22 words
The Faraday rotator of claim 1 wherin each of said tuning magnets has a length of from about 0.4L to about 0.7L.
Claim 4
Dependent Claim
18 words
The Faraday rotator of claim 2 wherein each of said tuning magnets has a specified length 1/2 L.
Claim 5
Dependent Claim
16 words
The Faraday rotator of claim 1 wherein each of said tuning magnets is a permanent magnet.
Claim 6
Dependent Claim
24 words
The Faraday rotator of claim 4 wherein each of said tuning magnets is a permanent magnet made of a material containing samarium and cobalt.
Claim 7
Dependent Claim
25 words
The Faraday rotator of claim 4 wherein each of said tuning magnets is a permanent magnet made of a material containing neodymium, iron, and boron.
Claim 8
Dependent Claim
148 words
An optical isolator comprising: an input polarizer or polarizing beams or waves of light; a Faraday rotator, said Faraday rotator comprising: an optical element having an optical axis, said optical element being made of a light transmitting material; a first magnet for generating a magnetic field along the optical axis of said optical element, said magnet having a front end and a rear end, said magnetic field being generated in one direction and said first magnet having a specified length 1.0L; and a pair of tuning magnets, each tuning magnet being located at a front end or a rear end of said first magnet, each tuning magnet generating a magnetic field in a direction opposite to the direction of the magnetic field being generated by said first magnet, and the total combined length of said tuning magnets being from about 0.8L to about 1.4L; and an output polarizer.
Claim 9
Dependent Claim
148 words
An optical isolator comprising: an input polarizer or polarizing beams or waves of light; a Faraday rotator, said Faraday rotator comprising: an optical element having an optical axis, said optical element being made of a light transmitting material; a first magnet for generating a magnetic field along the optical axis of said optical element, said magnet having a front end and a rear end, said magnetic field being generated in one direction and said first magnet having a specified length 1.0L; and a pair of tuning magnets, each tuning magnet being located at a front end or a rear end of said first magnet, each tuning magnet generating a magnetic field in a direction opposite to the direction of the magnetic field being generated by said first magnet, and the total combined length of said tuning magnets being from about 0.8L to about 1.4L; and an output polarizer.
Claim 10
Dependent Claim
22 words
The optical isolator of claim 7 wherein each of said tuning magnets has a length of from about 0.4L to about 0.7L.
Claim 11
Dependent Claim
18 words
The optical isolator of claim 8 wherein each of said tuning magnets has a specified length 1/2 L.
Claim 12
Dependent Claim
16 words
The optical isolator of claim 7 wherein each of said tuning magnets is a permanent magnet.
Claim 13
Dependent Claim
24 words
The optical isolator of claim 10 wherein each of said tuning magnets is a permanent magnet made of a material containing samarium and cobalt.
Claim 14
Dependent Claim
25 words
The optical isolator of claim 10 wherein each of said tuning magnets is a permanent magnet made of a material containing neodymium, iron, and boron.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-14 | 1993-02-13 | 1993-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-14 | 1997-02-13 | 1997-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-14 | 2001-02-13 | 2001-08-15 | $7700.00 | Window Closed / Lapsed |