US4575192A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of bragg angle adjustments for copying holograms
Assignee: United States Department of the Army
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Filing: 1983-10-11
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Granted: 1986-03-11
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Expires: 2003-10-11
Abstract
Abstract A method of copying a thick hologram, recorded at wavelength lambda 1, so that the copy can be efficiently read out with a beam lambda 3 at the same incident angle as used to efficiently read out the original. The method involves copying the hologram using wavelength lambda 2 at a predetermined incident angle, which incident angle provides fringe angles in the copy to yield maximum diffraction efficiency of the read-out beam lambda 3.
Inventors
- 👤 Joseph G. M. Duthie
- 👤 Charles R. Christensen
- 👤 Carl D. Leonard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:15
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/04; G03H1/20; G03H1/202; G03H1/0402; G03H2001/0415; G03H2001/0417; G03H2260/00; G03H2260/10; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
165 words
A method of copying a thick master holographic optical element, which element at wavelength λ 1 would be read out at at optimal efficiency at incident beam angle ξ 3 =ξ 1 , so that a copy hologram can be read out at optimal efficiency at incident angle ξ 3 =ξ 1 but at wavelength λ 3 , said method comprising the steps of: (a) placing said thick master holographic optical element adjacent a copy plate having a thick emulsion thereon; (b) directing radiation at wavelength λ 2 and at predetermined incident angle ξ 2 onto said thick master holographic element and adjacent copy plate; (c) developing the copy plate emulsion to form the copy hologram; (d) illuminating the copy hologram with radiation at wavelength λ 3 and at the incident angle ξ 3 =ξ 1 ; wherein the predetermined incident angle ξ 2 is determined so that the resulting fringe plane angles in the copy hologram satisfy the Bragg condition for step (d) above.
Claim 2
Independent Claim
165 words
A method of copying a thick master holographic optical element, which element at wavelength λ 1 would be read out at at optimal efficiency at incident beam angle ξ 3 =ξ 1 , so that a copy hologram can be read out at optimal efficiency at incident angle ξ 3 =ξ 1 but at wavelength λ 3 , said method comprising the steps of: (a) placing said thick master holographic optical element adjacent a copy plate having a thick emulsion thereon; (b) directing radiation at wavelength λ 2 and at predetermined incident angle ξ 2 onto said thick master holographic element and adjacent copy plate; (c) developing the copy plate emulsion to form the copy hologram; (d) illuminating the copy hologram with radiation at wavelength λ 3 and at the incident angle ξ 3 =ξ 1 ; wherein the predetermined incident angle ξ 2 is determined so that the resulting fringe plane angles in the copy hologram satisfy the Bragg condition for step (d) above.
References Cited (Backward Citations)
US3639031A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-03-10 | 1989-09-09 | 1990-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-10 | 1993-09-09 | 1994-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-10 | 1997-09-09 | 1998-03-11 | $7700.00 | Window Closed / Lapsed |