COPYING DEVICE AND METHOD FOR GENERATING A REPLICATION HOLOGRAM

Abstract

A copying device for generating a replication hologram that represents a copy of a master hologram. The device includes an object hologram for generating an object wave via a master signal, and a reference hologram for generating a reference wave with the aid of the master signal.

Claims

1-10 (canceled)

11. A copying device for generating a replication hologram that represents a copy of a master hologram, the device comprising: an object hologram configured to generate an object wave via a master signal; and a reference hologram configured to generate a reference wave using the master signal, the object hologram and the reference hologram being configured in such a way that via irradiation with the master signal, the generated object wave intersects with the generated reference wave in a plane in which a photosensitive layer for forming the replication hologram, into which an interference pattern is writable by exposure, is situated.

12. The copying device as recited in claim 11, wherein the object hologram and/or the reference hologram, is excitable by a flat wave front as the master signal, or by a spherical wave as the master signal, or by a cylindrical wave front as the master signal.

13. The copying device as recited in claim 11, wherein the master hologram is made up of at least two subholograms that are generatable by reference waves that are originally different.

14. The copying device as recited in claim 11, wherein the object hologram and/or the reference hologram, is situated in on an end side in an optical fiber that is configured as a glass plate, the optical fiber including a coupling hologram that is configured in such a way that the master signal is deflectable in a direction of the object hologram and/or of the reference hologram.

15. The copying device as recited in claim 13, wherein the object hologram and/or the reference hologram is configured in such a way that the object wave and/or the reference wave is formed with a varying emission direction for reducing transition areas between the at least two subholograms of the replication hologram to be generated.

16. The copying device as recited in claim 11, wherein the photosensitive layer is situated for forming the replication hologram in such a way that the reference wave defined using the reference hologram and the object wave defined using the object hologram, impact on the photosensitive layer from opposite sides.

17. The copying device as recited in claim 11, wherein the photosensitive layer is configured to be pushed through the copying device step by step for creating a plurality of replication holograms.

18. A copying method for generating a replication hologram that represents a copy of a master hologram, the copying device including an object hologram configured to generate an object wave via a master signal, and a reference hologram configured to generate a reference wave using the master signal, the object hologram and the reference hologram being configured in such a way that via irradiation with the master signal, the generated object wave intersects with the generated reference wave in a plane in which a photosensitive layer for forming the replication hologram, into which an interference pattern is writable by exposure, is situated, the copying method comprising the following steps: situating the photosensitive layer in the plane for forming the replication hologram by exposing the photosensitive layer with an interference pattern of the reference wave to be generated and the object wave to be generated; irradiating the reference hologram with the master signal for generating the reference wave; and simultaneously irradiating the object hologram for generating the object wave with the master signal.

19. The copying method as recited in claim 18, wherein the master signal in the reference hologram is transformed from the master signal to form the reference wave, and/or the master signal in the object hologram is transformed to form the object wave.

20. The copying method as recited in claim 18, wherein the photosensitive layer is pushed step by step through the copying device for forming the reference hologram as a copy of the master hologram for generating a plurality of replication holograms.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG. 1 shows a schematic illustration of one preferred specific embodiment of the copying device according to the present invention, in a side view.

[0019] FIG. 2 shows a schematic illustration of one refinement of the copying device according to the present invention known from FIG. 1, likewise in a side view.

[0020] Functionally identical or equivalent elements and assemblies are denoted by the same reference numerals in the figures.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0021] FIG. 1 shows a copying device 1 according to the present invention in one preferred specific embodiment of the present invention, in a side view. Copying device 1 according to the present invention includes an object hologram 2 and a reference hologram 3 that are spaced apart from one another along a depth axis T. Object hologram 2 on the end is situated in an optical fiber 6 designed as a glass plate 4, glass plate 4 extending along a longitudinal axis L. A coupling hologram 5 is situated (diagonally) in glass plate 4 in the end opposite from object hologram 2 with respect to longitudinal axis L. A photosensitive layer 8 is situated in the area of object hologram 2, between object hologram 2 and reference hologram 3, in a plane 7 parallel to longitudinal axis L. In addition, reference hologram 3 is situated in a waveguide 6 designed as a glass plate 4, glass plate 4 accommodating a coupling hologram 5 in an end opposite from reference hologram 3 along longitudinal axis L.

[0022] During operation, an original source 11, only schematically illustrated in FIG. 1, generates a master signal 9, which with the aid of an optical element 12 is converted into a master signal 9 that includes a flat wave front 10 and that is also aligned with one of the coupling holograms 5. Flat wave front 10 of master signal 9 thus impacts coupling hologram 5 situated in glass plate 4. Flat wave front 10 of master signal 9 is reflected at an angle a that is greater than the total reflection angle of glass plate 4. For this reason, flat wave front 10 of master signal 9 now propagates within glass plate 4 along longitudinal axis L in the direction of photosensitive layer 8, and at the end impacts either object hologram 2 or reference hologram 3. Reference hologram 3 now fulfills two functions: on the one hand, master signal 9 is deflected in the direction of photosensitive layer 8, and on the other hand is also optically transformed in such a way that master signal 9, which includes flat wave front 10, is converted into an original reference wave 14 of a master hologram, not graphically illustrated. In addition, a deflection of master signal 9 (alignment) and an optical transformation for reproducing original object wave 13 (formation) of the master hologram take place in object hologram 2. According to the present invention, object wave 13 and reference wave 14 are deflected and aligned in such a way that object wave 13 and reference wave 14 form an interference pattern 15 precisely in plane 7 in which photosensitive layer 8 has been situated, the interference pattern then being written into photosensitive layer 8 by exposure. This allows photosensitive layer 8 to form replication hologram 16, which forms the copy of the master hologram, it also being possible for replication hologram 16 to be made up of multiple subholograms (hogels) 20.

[0023] FIG. 2 shows a schematic illustration of copying device la according to the present invention in one preferred refinement of the present invention, in a side view. Illustrated copying device 1a differs from copying device 1 known from FIG. 1, in that photosensitive layer 8 now extends along longitudinal axis L between the two glass plates 4 that accommodate reference hologram 3 or object hologram 2. Photosensitive layer 8 is step-by-step displaceably situated along longitudinal axis L. This allows implementation of an advantageously simple automation of the copying operation by copying device la according to the present invention.

[0024] During operation, photosensitive layer 8 is initially situated between the two glass plates 4 along longitudinal axis L in such a way that a section 17 of photosensitive layer 8 is situated in a target position 18 in the area of object hologram 2 and reference hologram 3. Object wave 14 and reference wave 13 are subsequently generated according to the discussion for FIG. 1, as the result of which interference pattern 15 may be imparted by exposure in section 17 of photosensitive layer 8, and replication hologram 16 may thus be completely formed as a copy of the master hologram. After replication hologram 16 is generated, photosensitive layer 8 is displaced by a tracking increment along longitudinal axis L, as the result of which finished replication hologram 16 leaves target position 18 and is displaced into end position 19. A new section 17 of photosensitive layer 8 is now situated in target position 18, from which a replication hologram 16 is once again generatable.

[0025] In one alternative specific embodiment of the present invention, a curved surface on which photosensitive layer 8 is applied may also be inserted between glass plates 4. The desired optical function may thus be defined, even in an arbitrarily shaped hologram. This is meaningful, for example, when holograms are to be subsequently applied to eyeglasses. Due to the recording in a curved shape, it may be prevented that the holographic grating is distorted due to curvature after the recording, thus impairing the optical function.

[0026] In addition, it is noted that secondary to the illustrated specific embodiments, copying device 1; 1a may also have other designs without departing from the scope of the present invention.