US4359260A
Expired / Lapsed
US
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Optical polarizer
Assignee: AT&T Inc
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Filing: 1980-06-25
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Granted: 1982-11-16
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Expires: 2000-06-25
Abstract
Abstract An optical polarizer is described in which a propagation layer (14) is covered with a dielectric buffer layer (16) and a metal layer (18). The thickness of the buffer layer is chosen so as to increase the attenuation of TM modes of radiation in the waveguide relative to TE modes. In accordance with the invention, additional discrimination between TM and TE modes is achieved by segmenting the metal layer into a plurality of tandem sections (18.1, 18.2, 18.3), thereby increasing the mode coupling loss for TM modes. A GaAs-AlGaAs rib waveguide polarizer is specifically described.
Inventors
- 👤 Franz K. Reinhart
- 👤 James C. Shelton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:01
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/126; G02B2006/12083; G02B2006/12097
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
112 words
An optical polarizer comprising a propagation layer (14) of material for carrying optical radiation (22) in both TE and TM modes, a dielectric layer (16) on said propagation layer and having a lower optical dielectric constant than said propagation layer, a metal layer (18) on said dielectric layer, the thickness (W ox ) of said dielectric layer being chosen so as to increase the attenuation of said TM modes relative to said TE modes, characterized in that said metal layer comprises a plurality of separate segments (18.1, 18.2, 18.3) arranged in tandem on said propagation layer so as to increase the coupling loss of said TM modes relative to said TE modes.
Claim 2
Dependent Claim
112 words
An optical polarizer comprising a propagation layer (14) of material for carrying optical radiation (22) in both TE and TM modes, a dielectric layer (16) on said propagation layer and having a lower optical dielectric constant than said propagation layer, a metal layer (18) on said dielectric layer, the thickness (W ox ) of said dielectric layer being chosen so as to increase the attenuation of said TM modes relative to said TE modes, characterized in that said metal layer comprises a plurality of separate segments (18.1, 18.2, 18.3) arranged in tandem on said propagation layer so as to increase the coupling loss of said TM modes relative to said TE modes.
Claim 3
Dependent Claim
20 words
The polarizer of claim 1 further including means for lateral guiding the propagation of said radiation in said propagation layer.
Claim 4
Dependent Claim
17 words
The polarizer of claim 2 wherein said guiding means comprises an elongated rib on said propagation layer.
Claim 5
Dependent Claim
39 words
The polarizer of claims 1, 2, or 3 wherein the thickness of said dielectric layer is chosen so that the attenuation of the TM 1 modes is near a peak in the attenuation versus thickness characteristic of said polarizer.
Claim 6
Dependent Claim
26 words
The polarizer of claims 1, 2, or 3 wherein the thickness of said dielectric layer is chosen so the TM 1 mode is essentially cut off.
Claim 7
Dependent Claim
47 words
The polarizer of claims 1, 2, or 3 wherein said material of said propagation layer is a semiconductor and further including a semiconductor cladding layer, said propagation layer being formed on said cladding layer and of a material having a higher dielectric constant than said cladding layer.
Claim 8
Dependent Claim
27 words
The polarizer of claim 6 wherein said cladding layer comprises Al x Ga 1-x As, 0<x≦1 and said propagation layer comprises Al y Ga 1-y As, 0≦y<x.
Claim 9
Dependent Claim
17 words
The polarizer of claim 7 wherein said dielectric layer comprises a native oxide of said propagation layer.
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) | 1985-11-15 | 1986-05-17 | 1986-11-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-15 | 1990-05-17 | 1990-11-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-15 | 1994-05-17 | 1994-11-16 | $7700.00 | Window Closed / Lapsed |