Patent US3847465A successfully refreshed from Google Patents.
US3847465A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hologram formation within a polycrystalline photo excitable electro-optic plate
Assignee: Thales SA
•
Filing: 1972-11-14
•
Granted: 1974-11-12
•
Expires: 1992-11-14
Abstract
Abstract The present invention relates to holographic systems embodying a phase hologram pattern formed within the volume of a photoexcitable, electro-optic material. The system in accordance with the present invention comprises a pattern of fringes formed in a photo-excitable polycrystalline material of quasi-theoretical density. A biased state is created electrically or by mechanical stress, in the polycristalline material in order to permit the formation of an electronic density modulation condition capable of exploitation by electrooptical effect.
Inventors
- 👤 F Micheron
- 👤 G Bismuth
- 👤 A Hermasin
- 👤 J Nicolas
- 👤 M Hildebrandt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:28
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/02; G02; G02F; G02F1/00; G02F1/01; G02F1/03; G02F1/055; G02F1/0558; G03H1/024; G03H1/0248; G03H2260/00; G03H2260/50; G03H2260/54
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
115 words
OPTICAL SYSTEM WITH PHOTO-INDUCED HOLOGRAPHIC PATTERN COMPRISING: A PLATE CONSISTING OF PHOTOEXCITABLE ELECTRO-OPTIC MATERIAL HAVING A POLYCRYSTALLINE STRUCTURE, PHOTO-INDUCING MEANS POSITIONED FOR IRRADIATING SAID PLATE WITH A PATTERN OF INTERFERENCE FRINGES, AND BIAS MEANS FOR GENERATING WITHIN THE VOLUME OF SAID PLATE A PREDETERMINED UNIFORM STATE OF ELECTRICAL POLARIZATION; SAID MATERIAL HAVING A DENSITY DIFFERING FROM ITS THEORETICAL DENSITY BY LESS THAN FIVE THOUSANDTHS; SAID PREDETERMINED STATE OF ELECTRICAL POLARIZATION BEING FORMED DURING THE WRITING-IN AND READING OUT PHASES OF SAID PATTERN OF INTERFERENCE FRINGES; SAID PATTERN OF INTERFERENCE FRINGES BEING CONSTRUCTED FROM THE INTERACTION OF TWO COHERENT BEAMS HAVING A MEAN DIRECTION OF INCIDENCE AT AN ANGLE WITH THE DIRECTION OF SAID ELECTRICAL POLARIZATION.
Claim 2
Dependent Claim
115 words
OPTICAL SYSTEM WITH PHOTO-INDUCED HOLOGRAPHIC PATTERN COMPRISING: A PLATE CONSISTING OF PHOTOEXCITABLE ELECTRO-OPTIC MATERIAL HAVING A POLYCRYSTALLINE STRUCTURE, PHOTO-INDUCING MEANS POSITIONED FOR IRRADIATING SAID PLATE WITH A PATTERN OF INTERFERENCE FRINGES, AND BIAS MEANS FOR GENERATING WITHIN THE VOLUME OF SAID PLATE A PREDETERMINED UNIFORM STATE OF ELECTRICAL POLARIZATION; SAID MATERIAL HAVING A DENSITY DIFFERING FROM ITS THEORETICAL DENSITY BY LESS THAN FIVE THOUSANDTHS; SAID PREDETERMINED STATE OF ELECTRICAL POLARIZATION BEING FORMED DURING THE WRITING-IN AND READING OUT PHASES OF SAID PATTERN OF INTERFERENCE FRINGES; SAID PATTERN OF INTERFERENCE FRINGES BEING CONSTRUCTED FROM THE INTERACTION OF TWO COHERENT BEAMS HAVING A MEAN DIRECTION OF INCIDENCE AT AN ANGLE WITH THE DIRECTION OF SAID ELECTRICAL POLARIZATION.
Claim 3
Dependent Claim
31 words
System as claimed in claim 1, wherein said bias means comprise at least one set of two electrodes arranged on said plate and an electrical excitation generator coupled to said electrodes.
Claim 4
Dependent Claim
20 words
System as claimed in claim 1, wherein said bias means comprise means for applying a mechanical stress to said plate.
Claim 5
Dependent Claim
13 words
System as claimed in claim 1, wherein said material is a ferroelectric material.
Claim 6
Dependent Claim
19 words
System as claimed in claim 4, wherein said ferroelectric material is a ferroelectric ceramic containing traces of metal impurities.
Claim 7
Dependent Claim
16 words
System as claimed in claim 5, wherein said ceramic is a lead and lanthanum titanium zirconate.
Claim 8
Dependent Claim
12 words
System as claimed in Claim 2, wherein said electrodes are concentric electrodes.
Claim 9
Dependent Claim
25 words
System as claimed in claim 2, wherein said electrodes comprise at least two crossed conductive bands deposited respectively upon the two faces of said plate.
Claim 10
Dependent Claim
16 words
System as claimed in claim 1, further comprising means for erasing said state of electrical polarization.
Claim 11
Dependent Claim
35 words
System as claimed in claim 9, wherein said further means comprise electrodes coupled to an electrical generator for inducing in at least one portion of said volume, an alternating debiasing field having a decreasing amplitude.
Claim 12
Dependent Claim
32 words
System as claimed in claim 1, wherein said bias means are adjustable bias means arranged for forming in succession at least two distinct electrical bias states within the volume of said plate.
Claim 13
Dependent Claim
17 words
System as claimed in claim 11, wherein said distinct states differ from one another by their amplitudes.
Claim 14
Dependent Claim
17 words
System as claimed in claim 11, wherein said distinct states differ from one another by their orientations.
Claim 15
Dependent Claim
47 words
System as claimed in claim 1, wherein said photoinducing means direct towards said volume an object beam and a reference beam; said beams being applied during the recording phase of said pattern and one of said beams only being applied during the read-out phase of said pattern.
Claim 16
Dependent Claim
31 words
System as claimed in claim 14, further comprising position control means for changing the orientation of said reference beam with each of the successive recording steps building up said recording phase.
References Cited (Backward Citations)
US3652145A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |