Patent US5078512A successfully refreshed from Google Patents.
US5078512A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Unidirectional mode converter and optical isolator using same
Assignee: National Institute of Advanced Industrial Science and Technology
•
Filing: 1991-02-20
•
Granted: 1992-01-07
•
Expires: 2011-02-20
Abstract
Abstract An optical isolator in which a mirror is arranged in the waveguide path to provide Fresnel reflection of the propagating light and change the light path direction by 90 degrees, the light path from the waveguide input plane to the mirror forms a first region in which magneto-optic-induced non-reciprocal mode conversion takes place, and the part of the light path from the mirror to the waveguide output plane forms a second region in which reciprocal mode conversion takes place, and mode selectors or polarizers are provided at the light input and output planes.
Inventors
- 👤 Koji Ando
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 01:34
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/126; G02F; G02F1/00; G02F1/01; G02F1/09; G02F1/095; G02F1/0955
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
121 words
A unidirectional mode converter comprising: a first waveguide path having an input plane at one end; a second waveguide path arranged at right angles to the first waveguide path and having an output plane at one end; a Fresnel reflection mirror provided at the point of intersection between the first and second waveguide paths at an angle of 45 degrees to each waveguide path; magnetization means for magnetizing each of the first and second waveguide paths so that the direction of magnetization of each of the paths differs from the direction of light propagation along each path; whereby the first waveguide path forms a Faraday-effect-induced non-reciprocal mode conversion region and the second waveguide path forms a Cotton-Mouton-effect-induced reciprocal mode conversion region.
Claim 2
Dependent Claim
121 words
A unidirectional mode converter comprising: a first waveguide path having an input plane at one end; a second waveguide path arranged at right angles to the first waveguide path and having an output plane at one end; a Fresnel reflection mirror provided at the point of intersection between the first and second waveguide paths at an angle of 45 degrees to each waveguide path; magnetization means for magnetizing each of the first and second waveguide paths so that the direction of magnetization of each of the paths differs from the direction of light propagation along each path; whereby the first waveguide path forms a Faraday-effect-induced non-reciprocal mode conversion region and the second waveguide path forms a Cotton-Mouton-effect-induced reciprocal mode conversion region.
Claim 3
Dependent Claim
23 words
A unidirectional mode converter according to claim 1 in which the tilt angle of the magnetization by the magnetization means is 45 degrees.
Claim 4
Dependent Claim
123 words
An optical isolator comprising: a first waveguide path having an input plane at one end; a second waveguide path arranged at right angles to the first waveguide path and having an output plane at one end; a Fresnel reflection mirror provided at the point of intersection between the first and second waveguide paths at an angle of 45 degrees to each waveguide path; magnetization means for magnetizing each of the first and second waveguide paths so that the direction of magnetization of each of the paths differs from the direction of light propagation along each path; a mode selector provided at the input plane of the first waveguide path; and a mode selector provided at the output plane of the second waveguide path.
Claim 5
Dependent Claim
123 words
An optical isolator comprising: a first waveguide path having an input plane at one end; a second waveguide path arranged at right angles to the first waveguide path and having an output plane at one end; a Fresnel reflection mirror provided at the point of intersection between the first and second waveguide paths at an angle of 45 degrees to each waveguide path; magnetization means for magnetizing each of the first and second waveguide paths so that the direction of magnetization of each of the paths differs from the direction of light propagation along each path; a mode selector provided at the input plane of the first waveguide path; and a mode selector provided at the output plane of the second waveguide path.
Claim 6
Dependent Claim
28 words
An optical isolator according to claim 3 in which the mode selectors provided at the input and output planes are of metal which selectively transmits prescribed light modes.
Claim 7
Dependent Claim
121 words
An optical isolator comprising: a first waveguide path having an input plane at one end; a second waveguide path arranged at right angles to the first waveguide path and having an output plane at one end; a Fresnel reflection mirror provided at the point of intersection between the first and second waveguide paths at an angle of 45 degrees to each waveguide path; magnetization means for magnetizing each of the first and second waveguide paths so that the direction of magnetization of each of the paths differs from the direction of light propagation along each path; a polarizer provided at the input plane of the first waveguide path; and a polarizer provided at the output plane of the second waveguide path.
Claim 8
Dependent Claim
121 words
An optical isolator comprising: a first waveguide path having an input plane at one end; a second waveguide path arranged at right angles to the first waveguide path and having an output plane at one end; a Fresnel reflection mirror provided at the point of intersection between the first and second waveguide paths at an angle of 45 degrees to each waveguide path; magnetization means for magnetizing each of the first and second waveguide paths so that the direction of magnetization of each of the paths differs from the direction of light propagation along each path; a polarizer provided at the input plane of the first waveguide path; and a polarizer provided at the output plane of the second waveguide path.
Claim 9
Dependent Claim
27 words
An optical isolator according to claim 5 in which the polarizers provided at the input and output planes are of metal which selectively absorbs prescribed light modes.
References Cited (Backward Citations)
US3995936A
Cited
US4575179A
Cited
US4707058A
Cited
US4712855A
Cited
US4877298A
Cited
US4859014A
Cited
US4898440A
Cited
US4973119A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-06 | 1995-07-08 | 1996-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-06 | 1999-07-08 | 2000-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-06 | 2003-07-08 | 2004-01-07 | $7700.00 | Window Closed / Lapsed |