US5175647A
Expired / Lapsed
US
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Optical device
Assignee: Eastman Kodak Co
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Filing: 1991-06-26
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Granted: 1992-12-29
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Expires: 2011-06-26
Abstract
Abstract An optical device is disclosed for diffracting an incident beam of radiation to form a plurality of discrete diffracted beams of different orders. The optical device comprises two diffraction gratings which are supported on a substrate and are separated from each other by a thin film. In order to obtain the advantages of a doubly-periodic structure, the thickness of the thin film between the two gratings is very accurately controlled to be on the order of the wavelength of the incident beam of radiation.
Inventors
- 👤 Mool C. Gupta
- 👤 Song-Tsuen Peng
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:14
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/42; G02B27/4272; G02B27/4233; G02B27/4238
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
87 words
An optical device for diffracting an incident beam or radiation to form a a plurality of discrete diffracted beams of different orders, said optical device comprising: a first diffraction grating formed in a substrate; and a second diffraction grating formed in a surface of said device, said first and said second gratings being uniformly spaced apart by a distance approximating the wavelength of said incident beam of radiation, wherein a spacing between said first and said second gratings is between about 0.1 μm and about 10.0 μm.
Claim 2
Dependent Claim
87 words
An optical device for diffracting an incident beam or radiation to form a a plurality of discrete diffracted beams of different orders, said optical device comprising: a first diffraction grating formed in a substrate; and a second diffraction grating formed in a surface of said device, said first and said second gratings being uniformly spaced apart by a distance approximating the wavelength of said incident beam of radiation, wherein a spacing between said first and said second gratings is between about 0.1 μm and about 10.0 μm.
Claim 3
Dependent Claim
18 words
The optical device, as defined by claim 1, wherein said first and said second gratings are substantially identical.
Claim 4
Dependent Claim
22 words
The optical device, as defined in claim 1, wherein said substrate is a transparent member having a thickness of about 0.5 millimeters.
Claim 5
Dependent Claim
30 words
The optical device, as defined in claim 3, wherein said first grating is formed in a reflective surface of the substrate, said substrate having a thickness of about 0.5 millimeters.
Claim 6
Dependent Claim
25 words
The optical device, as defined in claim 3, wherein said second grating is formed in a optically transparent thin film disposed on said first grating.
Claim 7
Dependent Claim
13 words
The optical device, as defined in claim 5, wherein said substrate comprises quartz.
Claim 8
Dependent Claim
14 words
The optical device, as defined in claim 6, wherein said thin film comprises quartz.
Claim 9
Dependent Claim
19 words
The optical device, as defined in claim 7, wherein said first grating has a period of about 0.36 μm.
Claim 10
Dependent Claim
18 words
The optical device, as defined by claim 8, wherein said second grating has period of about 0.45 μm.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-12-29 | 1996-06-29 | 1996-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-12-29 | 2000-06-29 | 2000-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-12-29 | 2004-06-29 | 2004-12-29 | $7700.00 | Window Closed / Lapsed |