Patent US4799746A successfully refreshed from Google Patents.
US4799746A
Expired / Lapsed
US
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Efficient holograms and method for making same
Assignee: Raytheon Co
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Filing: 1985-02-27
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Granted: 1989-01-24
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Expires: 2005-02-27
Abstract
Abstract Light sensitive recording medium is exposed to highly absorbed incoherent light either before or after a slant fringe hologram is recorded therein to reduce the sensitivity of the medium at surface regions adjacent a supporting substrate. The fringes recorded in the area of reduced sensitivity have lower contrast than those recorded in the remainder of the medium, freeing the fringes from the substrate and allowing greater expansion of the medium during a subsequent chemical swelling process. The increased swelling amplifies the refractive index modulation in the medium to increase the diffraction efficiency of the hologram. Dye may be added to the medium to increase absorbance of the incoherent light.
Inventors
- 👤 John E. Wreede
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:28
CPC Classifications
G; G11; G11B; G11B7/00; G11B7/004; G11B7/0065; G03; G03C; G03C1/00; G03C1/66; G03H; G03H1/00; G03H1/04; G03H1/18; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
72 words
Method for making slant fringe holograms having increased efficiency comprising: applying a single layer of light sensitive holographic recording medium to a single surface of a substrate; treating said layer to reduce light sensitivity at only surface regions thereof adjacent said single surface of said substrate, said treating comprising exposing the medium to highly absorbed incoherent light; and exposing the recording medium to coherent light to record a slant fringe pattern therein.
Claim 2
Dependent Claim
72 words
Method for making slant fringe holograms having increased efficiency comprising: applying a single layer of light sensitive holographic recording medium to a single surface of a substrate; treating said layer to reduce light sensitivity at only surface regions thereof adjacent said single surface of said substrate, said treating comprising exposing the medium to highly absorbed incoherent light; and exposing the recording medium to coherent light to record a slant fringe pattern therein.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein the medium is dichromated gelatin and the incoherent light is at a wavelength of about 3660 Angstroms.
Claim 4
Dependent Claim
17 words
The method of claim 1 wherein the medium includes dye which promotes absorbance of said incoherent light.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein the medium is applied to a thickness of about 6-25 microns.
Claim 6
Dependent Claim
62 words
Method for making slant fringe holograms having increasing efficiency comprising: applying a single layer of light sensitive holographic recording medium to a single surface of a substrate; exposing the medium to highly absorbed incoherent light to reduce light sensitivity at only surface regions thereof adjacent said substrate; and exposing the recording medium to coherent light to record a slant fringe pattern therein.
Claim 7
Dependent Claim
62 words
Method for making slant fringe holograms having increasing efficiency comprising: applying a single layer of light sensitive holographic recording medium to a single surface of a substrate; exposing the medium to highly absorbed incoherent light to reduce light sensitivity at only surface regions thereof adjacent said substrate; and exposing the recording medium to coherent light to record a slant fringe pattern therein.
Claim 8
Dependent Claim
75 words
Method for increasing efficiency in slant fringe holograms comprising: applying a single layer of light sensitive holographic recording medium to a single surface of a substrate; treating said layer to reduce light sensitivity at only surface regions thereof adjacent said single surface of said substrate, said treating comprising exposing the medium to highly absorbed incoherent light; exposing the recording medium to coherent light to record a slant fringe pattern therein; and swelling the recording medium.
Claim 9
Dependent Claim
75 words
Method for increasing efficiency in slant fringe holograms comprising: applying a single layer of light sensitive holographic recording medium to a single surface of a substrate; treating said layer to reduce light sensitivity at only surface regions thereof adjacent said single surface of said substrate, said treating comprising exposing the medium to highly absorbed incoherent light; exposing the recording medium to coherent light to record a slant fringe pattern therein; and swelling the recording medium.
Claim 10
Dependent Claim
23 words
The method of claim 6 wherein the medium is dichromated gelatin and the incoherent light is at a wavelength of about 3660 Angstroms.
Claim 11
Dependent Claim
17 words
The method of claim 6 wherein the medium includes dye which promotes absorbance of said incoherent light.
Claim 12
Dependent Claim
17 words
The method of claim 6 wherein the medium is applied to a thickness of about 6-25 microns.
Claim 13
Dependent Claim
61 words
Method for making slant fringe holograms having increasing efficiency comprising: applying a single layer of light sensitive holographic recording medium to a single surface of substrate; exposing the recording medium to coherent light to record a slant fringe pattern therein; and exposing the medium to highly absorbed incoherent light to reduce light sensitivity at only surface regions thereof adjacent said substrate.
Claim 14
Dependent Claim
61 words
Method for making slant fringe holograms having increasing efficiency comprising: applying a single layer of light sensitive holographic recording medium to a single surface of substrate; exposing the recording medium to coherent light to record a slant fringe pattern therein; and exposing the medium to highly absorbed incoherent light to reduce light sensitivity at only surface regions thereof adjacent said substrate.
Claim 15
Dependent Claim
66 words
A slant fringe hologram having increased efficiency comprising a substrate and a single layer of holographic recording mounted on a single surface of said substrate, said layer having a slant fringe pattern recorded therein, the fringe pattern at only surface regions of the medium adjacent the surface of the substrate being substantially reduced in contrast from the fringe pattern in the interior of the holographic medium.
Claim 16
Dependent Claim
66 words
A slant fringe hologram having increased efficiency comprising a substrate and a single layer of holographic recording mounted on a single surface of said substrate, said layer having a slant fringe pattern recorded therein, the fringe pattern at only surface regions of the medium adjacent the surface of the substrate being substantially reduced in contrast from the fringe pattern in the interior of the holographic medium.
References Cited (Backward Citations)
US3012886A
Cited
US2947626A
Cited
GB1371121A
Cited
FR2249364A1
Cited
US3940204A
Cited
JPS5719084A
Cited
EP0043993A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-01-24 | 1992-07-25 | 1993-01-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-24 | 1996-07-25 | 1997-01-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-24 | 2000-07-25 | 2001-01-24 | $7700.00 | Window Closed / Lapsed |