US5037168A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical waveguides
Assignee: BAE Systems Electronics Ltd
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Filing: 1989-08-31
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Granted: 1991-08-06
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Expires: 2009-08-31
Abstract
Abstract A smoothing layer is provided between the rough etched sides of a channel in a substrate in which an optical waveguiding material is to be produced. Losses are substantially reduced thereby. For a rectangular or rib waveguide, where the sides of the rib are left rough by etching, a smoothing layer is again provided over the rib. The smoothing layer preferably has a refractive index close to or the same as the materials having surface roughness.
Inventors
- 👤 Terence P. Young
- 👤 Philip H. Wisbey
- 👤 Nicholas A. Davies
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:42
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/061; G02F1/065; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/122
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
60 words
An optical waveguide comprising an elongate body of an active polymeric waveguiding material of first refractive index located in a channel formed in a substrate material of lower refractive index; and a polymeric smoothing layer having a lower refractive index than said waveguiding material, said smoothing layer being located in said channel between said elongate body and said substrate material.
Claim 2
Dependent Claim
60 words
An optical waveguide comprising an elongate body of an active polymeric waveguiding material of first refractive index located in a channel formed in a substrate material of lower refractive index; and a polymeric smoothing layer having a lower refractive index than said waveguiding material, said smoothing layer being located in said channel between said elongate body and said substrate material.
Claim 3
Dependent Claim
26 words
An optical waveguide according to claim 1, wherein said smoothing layer comprises a material having a refractive index substantially equal to that of said substrate material.
Claim 4
Dependent Claim
157 words
An optical waveguide comprising: a substrate member including a first buffer layer having a channel therein defined by a wall of given roughness, said first buffer layer having a refractive index n 2 ; an elongate body composed of an active polymeric waveguiding material located in said channel, said elongate body having a refractive index n 1 , where n 1 is greater than n 2 ; a polymeric smoothing layer located in said channel between said elongate body and said first buffer layer, said smoothing layer having a refractive index which is lower than the refractive index n 1 of said first buffer layer; and a second buffer layer on said elongate body, said second buffer layer having a refractive index n 3 which is lower than n 1 , said smoothing layer producing an interface having a roughness substantially less than that of said given roughness between said elongate body and said first buffer layer.
Claim 5
Dependent Claim
157 words
An optical waveguide comprising: a substrate member including a first buffer layer having a channel therein defined by a wall of given roughness, said first buffer layer having a refractive index n 2 ; an elongate body composed of an active polymeric waveguiding material located in said channel, said elongate body having a refractive index n 1 , where n 1 is greater than n 2 ; a polymeric smoothing layer located in said channel between said elongate body and said first buffer layer, said smoothing layer having a refractive index which is lower than the refractive index n 1 of said first buffer layer; and a second buffer layer on said elongate body, said second buffer layer having a refractive index n 3 which is lower than n 1 , said smoothing layer producing an interface having a roughness substantially less than that of said given roughness between said elongate body and said first buffer layer.
Claim 6
Dependent Claim
29 words
An optical waveguide according to claim 3 wherein the refractive index of said smoothing layer is substantially equal to the refractive index n 2 of said first buffer layer.
Claim 7
Dependent Claim
32 words
An optical waveguide according to claim 3 wherein the refractive index n 3 of said second buffer layer is substantially equal to the refractive index n 2 of said first buffer layer.
Claim 8
Dependent Claim
46 words
An optical waveguide according to claim 3 wherein said substrate member further comprises a substrate layer and a first electrode interposed between said substrate layer and said first buffer layer, and wherein said optical waveguide further includes a second electrode located on said second buffer layer.
Claim 9
Independent Claim
51 words
A method of forming an optical waveguide, comprising the steps of forming a channel in a substrate; providing a polymeric smoothing layer on the walls of the channel; and filling the channel with a polymeric waveguiding medium having a higher refractive index than those of the smoothing layer and the substrate.
Claim 10
Independent Claim
51 words
A method of forming an optical waveguide, comprising the steps of forming a channel in a substrate; providing a polymeric smoothing layer on the walls of the channel; and filling the channel with a polymeric waveguiding medium having a higher refractive index than those of the smoothing layer and the substrate.
Claim 11
Dependent Claim
21 words
A method according to claim 7, wherein the smoothing layer has a refractive index substantially equal to that of the substrate.
Claim 12
Dependent Claim
15 words
A method according to claim 8, wherein the channel is formed by etching the substrate.
References Cited (Backward Citations)
EP0149678A1
Cited
US4902086A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-08-05 | 1995-02-04 | 1995-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-08-05 | 1999-02-04 | 1999-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-08-05 | 2003-02-04 | 2003-08-06 | $7700.00 | Window Closed / Lapsed |