DE2338989C1 - Arrangement for the holographically encrypted recording of information - Google Patents
Arrangement for the holographically encrypted recording of informationInfo
- Publication number
- DE2338989C1 DE2338989C1 DE19732338989 DE2338989A DE2338989C1 DE 2338989 C1 DE2338989 C1 DE 2338989C1 DE 19732338989 DE19732338989 DE 19732338989 DE 2338989 A DE2338989 A DE 2338989A DE 2338989 C1 DE2338989 C1 DE 2338989C1
- Authority
- DE
- Germany
- Prior art keywords
- information
- arrangement
- holographically
- key
- diffuser
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000011521 glass Substances 0.000 claims description 6
- 239000011022 opal Substances 0.000 claims description 5
- 230000001427 coherent effect Effects 0.000 description 1
- 230000001010 compromised effect Effects 0.000 description 1
- 239000005338 frosted glass Substances 0.000 description 1
- 239000005337 ground glass Substances 0.000 description 1
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
- G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
- G03H1/0005—Adaptation of holography to specific applications
- G03H1/0011—Adaptation of holography to specific applications for security or authentication
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
- G03H1/00—Holographic processes or apparatus using light, infrared or ultraviolet waves for obtaining holograms or for obtaining an image from them; Details peculiar thereto
- G03H1/0005—Adaptation of holography to specific applications
- G03H1/0011—Adaptation of holography to specific applications for security or authentication
- G03H2001/0016—Covert holograms or holobjects requiring additional knowledge to be perceived, e.g. holobject reconstructed only under IR illumination
- G03H2001/0022—Deciphering being performed with numerical or optical key, e.g. with the optical scrambler used during recording
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03H—HOLOGRAPHIC PROCESSES OR APPARATUS
- G03H2223/00—Optical components
- G03H2223/14—Diffuser, e.g. lens array, random phase mask
Landscapes
- Engineering & Computer Science (AREA)
- Computer Security & Cryptography (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optical Recording Or Reproduction (AREA)
- Holo Graphy (AREA)
Description
Die vorliegende Erfindung betrifft eine Anordnung zur holo grafisch verschlüsselten Aufzeichnung von Informationen, wo bei entweder die Objektwelle oder die Referenzwelle einen Schlüsseldiffusor durchsetzen, bevor sie auf einem licht empfindlichen Speichermedium interferieren.The present invention relates to an arrangement for holo graphically encrypted record of information where with either the object wave or the reference wave one Push the key diffuser through on a light interfere with the sensitive storage medium.
Ein Hologramm entsteht im Prinzip durch das Interferenz system zweier kohärenter Wellen, der Objektwelle und der Referenzwelle. Die Referenzwelle ist dabei meist von ein facher Geometrie, während die Objektwelle die aufzunehmende Information enthält. Durch anschließende Beleuchtung des Hologramms mit der Referenzwelle wird die Objektwelle rekonstruiert.A hologram is basically created by interference system of two coherent waves, the object wave and the Reference wave. The reference wave is usually of one fold geometry, while the object wave is to be recorded Contains information. Subsequent lighting of the Hologram with the reference wave becomes the object wave reconstructed.
Ist die Objektwelle diffus, d.h. geht das Licht von jedem Objektpunkt in eine Vielzahl von Richtungen aus, so ist das im Hologramm aufgezeichnete Interferenzmuster völlig regel los und gestattet keinerlei Rückschlüsse auf die Information der Objektwelle. Dennoch ist die Information in einem solchen Hologramm im allgemeinen noch nicht verschlüsselt, weil sie durch Beleuchtung des Hologramms mit der einfachen Referenz welle zurückgewonnen werden kann.If the object wave is diffuse, i.e. the light goes from everyone Object point in a variety of directions, that's it interference pattern recorded in the hologram completely rule and does not allow any conclusions to be drawn about the information the object wave. Nevertheless, the information is in one Hologram in general not yet encrypted because it by illuminating the hologram with the simple reference wave can be recovered.
Wird aber zusätzlich eine der beiden zur Aufnahme gelangenden Wellen auf dem Weg zum Hologramm moduliert, etwa durch eine Mattscheibe im Strahlengang, so kann nur durch dieselbe Matt scheibe hindurch rekonstruiert werden. Die statistisch mo dulierende Mattscheibe stellt also einen Schlüssel, und zwar den einzigen zu der im Hologramm verschlüsselten Information dar.But will also be one of the two that will be accepted Waves modulated on the way to the hologram, for example by a Matt screen in the beam path, so only by the same matt be reconstructed through the slice. The statistically mo Dulating focusing screen is a key, namely the only one for the information encoded in the hologram represents.
Die bisher zur Codierung verwendeten Mattscheiben weisen eine Mattglasstruktur von etwa 2 bis 20 µm auf, die sich über die Oberfläche erstreckt. Aufgrund der Einfachstreuung an dieser flächenhaften Streuschicht sind einzelne Komponenten der Streuwelle nicht völlig unabhängig voneinander, wodurch die Codiersicherheit beeinträchtigt wird.The focusing screens previously used for coding have a Matt glass structure of about 2 to 20 µm, which extends over the Surface extends. Because of the single scatter on this areal scattering layer are individual components of the Stray wave not completely independent of each other, which makes the Coding security is compromised.
Aufgabe der vorliegenden Erfindung war es, eine Anordnung zur holografisch verschlüsselten Aufzeichnung von Informationen der eingangs genannten Art anzugeben, wobei durch den Einsatz eines neuartigen Schlüsseldiffusors eine erheblich höhere Codiersicherheit erzielt wird.The object of the present invention was to provide an arrangement for holographically encrypted recording of information of the type mentioned at the beginning, whereby through the use a new key diffuser a significantly higher one Coding security is achieved.
Zur Lösung dieser Aufgabe wird vorgeschlagen, daß der Schlüssel diffusor aus durchstrukturiertem Opalglas mit einer Dicke von 150 bis 300 µm besteht.To solve this problem it is proposed that the key diffuser made of structured opal glass with a thickness of 150 to 300 microns exists.
Von einem räumlichen Diffusor wird nicht nur verlangt, daß er eine Phasenmodulation ausführt, sondern auch, daß er eine Amplitudenmodulation der ihn durchsetzenden Lichtquelle aus führt. Es wurde gefunden, daß durchstrukturiertes Opalglas von einer Mindestdicke an unkorrelierte Ausgangswellen, aber im allgemeinen sehr viel schlechteres Signal/Rauschverhältnis als Mattglas rekonstruiert, liefert. Bei einer bestimmten Dicke jedoch, die im Bereich zwischen 150 und 300 µm liegt, und vorteilhafterweise 200 µm beträgt, liefert eine Schlüssel diffusorscheibe aus einem Opalglas ein vergleichbar gutes Signal/Rauschverhältnis wie eine Mattscheibe. Eine Opalglas dicke von 200 µm ist dabei gleichzeitig ausreichend, um die nullte ungebeugte Ordnung nicht bevorzugt durchzulassen.A spatial diffuser is not only required to be a phase modulation, but also that it has a Amplitude modulation of the light source passing through it leads. It was found that structured opal glass of a minimum thickness of uncorrelated output waves, however generally much worse signal-to-noise ratio reconstructed as frosted glass, delivers. At a certain However, the thickness, which is between 150 and 300 µm, and advantageously is 200 µm, provides a key diffuser disc made of an opal glass a comparably good one Signal / noise ratio like a ground glass. An opal glass A thickness of 200 µm is sufficient to achieve the not to pass through the zeroth undiffracted order preferentially.
Claims (2)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19732338989 DE2338989C1 (en) | 1973-08-01 | 1973-08-01 | Arrangement for the holographically encrypted recording of information |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19732338989 DE2338989C1 (en) | 1973-08-01 | 1973-08-01 | Arrangement for the holographically encrypted recording of information |
Publications (1)
Publication Number | Publication Date |
---|---|
DE2338989C1 true DE2338989C1 (en) | 1990-05-10 |
Family
ID=5888590
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE19732338989 Expired - Lifetime DE2338989C1 (en) | 1973-08-01 | 1973-08-01 | Arrangement for the holographically encrypted recording of information |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE2338989C1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2616236A1 (en) * | 1987-06-05 | 1988-12-09 | Kamoun Robert | Method for preparing the reference beam intended for recording a hologram |
-
1973
- 1973-08-01 DE DE19732338989 patent/DE2338989C1/en not_active Expired - Lifetime
Non-Patent Citations (1)
Title |
---|
NICHTS-ERMITTELT * |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2616236A1 (en) * | 1987-06-05 | 1988-12-09 | Kamoun Robert | Method for preparing the reference beam intended for recording a hologram |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
8100 | Publication of the examined application without publication of unexamined application | ||
D1 | Grant (no unexamined application published) patent law 81 |