Patent US4514479A successfully refreshed from Google Patents.
US4514479A
Expired / Lapsed
US
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Method of making near infrared polarizers
Assignee: United States Department of the Navy
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Filing: 1980-07-01
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Granted: 1985-04-30
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Expires: 2000-07-01
Abstract
Abstract A method of producing near infrared polarizers is disclosed using holograc techniques. The interference pattern from two intersecting laser beams is used to produce a plane grating in a layer of photoresist which has been deposited on a layer of conductive material which in turn has been used to coat a substrate. Ion milling reproduces the plane grating in the conductive material layer by selectively etching away a uniform level of material.
Inventors
- 👤 Ronald A. Ferrante
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:15
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/30; G02B5/3025; G02B5/3058; G02B5/32
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
129 words
A method of making thin film wire grid polarizers for the infrared spectral region comprising the steps of: coating a layer of material transparent to said spectral region on a substrate with high transmission in said spectral region; depositing a layer of photoresist over said coating; exposing said layer of photoresist to a two-beam laser interference pattern where a grating is recorded which is given as functions of the interbeam angle by the grating equation. ##EQU6## where ν=spatial frequency, n=photoresist refractive index, λ a =exposing wavelength, and θ o θ R =angle of incidence of object and reference waves measured in the photoresist: developing said exposed photoresist to produce a surface relief grating; and ion milling the surface relief grating to reproduce the relief surface in said transparent material.
Claim 2
Independent Claim
129 words
A method of making thin film wire grid polarizers for the infrared spectral region comprising the steps of: coating a layer of material transparent to said spectral region on a substrate with high transmission in said spectral region; depositing a layer of photoresist over said coating; exposing said layer of photoresist to a two-beam laser interference pattern where a grating is recorded which is given as functions of the interbeam angle by the grating equation. ##EQU6## where ν=spatial frequency, n=photoresist refractive index, λ a =exposing wavelength, and θ o θ R =angle of incidence of object and reference waves measured in the photoresist: developing said exposed photoresist to produce a surface relief grating; and ion milling the surface relief grating to reproduce the relief surface in said transparent material.
Claim 3
Dependent Claim
33 words
A method of making thin film wire grid polarizers for the infrared spectral region as described in claim 1 wherein said coating step further comprises a layer of material 100Å to 500Å thick.
Claim 4
Dependent Claim
34 words
A method of making thin film wire grid polarizers for the infrared spectral region as described in claim 1 wherein said depositing step further comprises a layer of photoresist 1 to 5 μm thick.
Claim 5
Dependent Claim
37 words
A method of making thin film wire grid polarizers for the infrared spectral region as described in claim 2 wherein said layer of material is chosen from the group consisting of aluminum, silver, gold, or indium oxide.
Claim 6
Dependent Claim
29 words
A method of making thin film wire grid polarizers for the infrared spectral region as described in claim 1 wherein said layer of photoresist is deposited by spin coating.
Claim 7
Dependent Claim
29 words
A method of making thin film wire grid polarizers for the infrared spectral region as described in claim 1 wherein said layer of photoresist is deposited by dip coating.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-29 | 1988-10-29 | 1989-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-29 | 1992-10-29 | 1993-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-29 | 1996-10-29 | 1997-04-30 | $7700.00 | Window Closed / Lapsed |