RU80968U1 - MULTIPLEX HOLOGRAM RECORDING DEVICE IN THE SYSTEM OF OPTICAL HOLOGRAPHIC MEMORY (OPTIONS) - Google Patents

Abstract

The invention relates to devices for recording multiplex holograms in an optical-holographic memory system. The proposed device for recording multiplex holograms in an optical holographic memory system allows using recording material with a thin photosensitive layer when recording, as well as providing the possibility of simultaneous recording of subholograms at the stage of recording information, and at the stage of reproducing information in a reader, simultaneously recovering images from all subholograms in the composition multiplex hologram. This result is achieved due to the fact that a rotation mechanism of the recording medium relative to the recording head is introduced into the multiplex hologram recording device, and the rotation axis coincides with the axis of the reference beam. In addition, a similar result is achieved by creating a recording head in the form of a multi-channel module with the number of channels corresponding to the number of subholograms in the multiplex hologram when they are concentric with respect to the axis of the reference beam. The implementation of this utility model provides the ability to work using thin, ultimately 2-dimensional, recording materials, in particular materials with silver halide photosensitive layers. Such materials are commercially available and relatively inexpensive. The use of a multi-channel recording head in the device, and during subsequent reading of a multi-channel reading head with simultaneous operation of the channels both at the recording stage and at the reading stage, provides correspondingly higher write and read speeds of information. The claims consist of 2 points on 2 pages. The description includes 2 figures

Description

Technical field

The technical solution relates to holographic systems for recording information

State of the art

Known devices for recording multiplex holograms operating as part of holographic systems for recording and reproducing information. These devices include a coherent optical radiation source (laser), a beam splitter, which divides the laser radiation into two parts, one of which is used to form the object beam and contains along the rays in front of the recording medium optical elements to expand the radiation beam and a recording head in the matrix device for input recording information and a Fourier transform lens, the other part is used to form the reference beam and contains optical elements to provide of a single reference beam configuration in the field of recording information on a recording medium, while multiple recording (multiplexing) of holograms in the field of beam reduction in one section of the recording medium is performed using deflecting devices installed in the subject (US No. 7, 209, 270 B2 of Apr. 24, 2007 [1]) or reference beams (US Pat. 2007/0121184 USA. MKI G03H

1/26, claimed 26.11.04; publ. 05/31/07 [2]) and providing a change in the relative angular position of the subject and reference beams for recording each of the individual holograms (subholograms) as part of a multiplex hologram. The disadvantage of these devices is the need to use 3-dimensional (thick) photosensitive media as recording materials, providing the necessary high angular selectivity of the recorded subholograms with respect to the reading beam and, accordingly, their separate restoration. Such recording materials are currently relatively scarce and expensive.

As a prototype adopted the closest in technical essence to the claimed device for recording multiplex holograms (US No. 6, 958, 967 B2 of Oct. 25, 2005 [3]), in which the reference beam is directed perpendicular to the surface of the recording medium, and at a constant relative position subject and reference beams, multiplexing is performed using a linear displacement device of the recording medium in a plane parallel to the surface of the medium, by a value significantly less than the size of the recorded hologram we. This device also has the disadvantage noted above. The property of all the multiplex hologram recording devices discussed above is the possibility at the stage of reproducing information of only sequential image recovery from each of the subholograms by changing the angular position of the reading beam relative to the recording medium [1, 2], or by linearly shifting the recording medium relative to the reading beam [3]. This limits the speed of recording and playing back information.

The essence of the utility model.

The objective of the utility model is to create a device for recording multiplex holograms in a system of optical-holographic memory with the elimination of the disadvantages of analogues and prototype.

The technical result of the utility model is the use of recording material with a thin photosensitive layer, as well as providing the possibility of simultaneous recording of subholograms at the stage of recording information, and at the stage of reproducing information in the reader, the simultaneous restoration of the image from all subholograms as part of a multiplex hologram.

The technical result is achieved due to the fact that in the device for recording multiplex holograms containing a laser, a beam splitter that divides the laser radiation into two parts, one of which is used to form the object beam and contains along the rays in front of the recording medium optical elements for expanding the radiation beam and recording a head as part of a matrix device for inputting recorded information and a Fourier transform lens, the other part is used to form a reference beam and contains op of sul elements to provide the necessary configuration of the reference beam in recording information on the recording medium with perpendicular incidence of the reference beam on the surface of the recording medium, introduced a device that provides for recording of each subgologrammy relative rotation of the recording head and the recording medium, wherein the rotation axis coincides with the reference beam axis.

Description of utility model and figures.

Figure 1 shows a variant of the optical design of a device for recording multiplex holograms using a single-channel recording

heads when multiplexing is carried out by turning the plate with a photosensitive layer.

Figure 2 presents a variant of the optical design of a device for recording multiplex holograms using a multi-channel recording head.

The radiation of the laser 1 (Fig. 1) after passing through the window of the shutter 2, providing the necessary exposure time of the photosensitive layer, the beam splitter 3 (amplitude beam splitter) is divided into subject and reference beams. After reflection by a flat mirror 4, which provides the desired configuration of the optical scheme, the object beam passes through the filtration and expansion unit as part of the micro-lens 5 and pinhole diaphragm 6 and enters the recording head as part of the Fourier transform lens (FPO) 7 and the space-time matrix light modulator (PVMS) 8. When an array of information is electronically fed to the input of the PVMS, a correspondingly modulated radiation field is formed in the PVMS window, the frequency spectrum of which is formed in the image plane the diaphragm 6 FPO 7 in the immediate vicinity of the surface of the photosensitive layer on the recording plate 13. The reference beam behind the beam splitter 3 after passing through the micro-lens 9 and the pinhole 10 is expanded and filtered and then collimated by the lens 11. Holographic recording of information is carried out by recording the interference field of the photosensitive medium on plate 13 at the intersection of the subject and reference beams in the area bounded by the diaphragm 12. Recording subholograms that make up a separate multiplex hologram is performed by stepwise rotate the photographic plate with turning axis coinciding with the axis of the reference beam by a three-axis table, on which the fixed plate. The lower part of the table 16, which is rotary, provides the necessary angular coordinate φ of the subglogram, the two upper parts 14 and

15 provide for the displacement of the photographic plate in the plane coinciding with its surface in the X and Y coordinates, thus determining the position of the multiplex hologram in the total array of multiplex holograms on the surface of the photographic plate.

In another embodiment of the multiplex hologram recording device (Fig. 2), the recording head is multi-channel with the number of channels corresponding to the number of subholograms in the multiplex hologram (up to 20), with their concentric position relative to the axis of the reference beam, and the photographic plate does not rotate. Here, the radiation of laser 1 after passing through the window of the shutter 2 and reflected by a flat mirror 4 (in figures 1 and 2, the elements of optical circuits having the same serial numbers are functionally identical) is expanded and filtered by a system consisting of a micro lens 9 and a pinhole 10 and then collimated by the lens 11 In the scheme, the spatial division of the total collimated radiation beam into the reference and object beams is carried out according to the number of channels of the recording head. For simplicity of the image on the optical scheme in figure 2 presents only two diametrically opposite channels of the multichannel recording head. The central part of the collimated beam is used as a reference beam incident on a photosensitive medium perpendicular to its surface. The peripheral annular part of the collimated beam by a system of mirrors 16 and 17 is distributed along the channels of the multichannel recording head located symmetrically with respect to the axis of the reference beam. In each channel, the radiation is filtered by a system consisting of a lens 5 and a pinhole 6 and, after passing through the shutter window 18, enters the FPO 7 and PVMS 8. The holographic recording of information is carried out by recording the interference field on the plate 13 at the intersection of the subject and reference beams in the area limited by aperture 12. Electronic control of the shutter provides the ability to record subholograms as simultaneously

with the simultaneous opening of the shutter 2 and the shutters 18 in all channels of the recording head, and sequential fast recording of subholograms with the shutters being opened one by one 18. To record the entire array of multiplex holograms, the recording plate of the photographic plate is moved in the plane coinciding with its surface along the X and Y coordinates using a two-coordinate table in parts 14 and 15.

When reading information from a multiplex hologram recorded using a recording device made in any of the considered options, the radiation beams from all subholograms that make up the multiplex hologram are restored simultaneously, while these beams are spatially separated. Reading information is carried out using a multi-channel read head with the number of reading channels equal to the number of recorded subholograms.

The implementation of this utility model provides the ability to work using thin, ultimately 2-dimensional, recording materials, in particular materials with silver halide photosensitive layers. Such materials are commercially available and relatively inexpensive. The use of a multi-channel recording head in the device, and during subsequent reading of a multi-channel reading head with simultaneous operation of the channels both at the recording stage and at the reading stage, provides correspondingly higher write and read speeds of information.

Literature

1. Kevin R. Curtis. Method and apparatus for phase correlation holographic drive. Patent USA No.US 7, 209, 270 B2 of Apr. 24, 2007.

2. Pat. 2007/0121184 United States. MKI G03H 1/26. Holographic storage device / Willem Marie Julia Marcel Coene (Netherlands); KONINKLIJKE PHILIPS ELECTRONICS (Netherlands). Announced on 11/26/04; Publ. 05/31/07.

3. Ken'ichi Kasazumi et al. Holographic optical information recording / reprodusing device. Patent USA No.US 6, 958, 967 B2 of Oct. 25, 2005.

Claims (2)

1. A device for recording multiplex holograms in an optical-holographic memory system, including a laser, a beam splitter, which divides the laser radiation into two parts, one of which is used to form the object beam and contains optical elements in front of the recording medium to expand the radiation beam and a recording head As part of a matrix device for inputting recorded information and a Fourier transform lens, the other part is used to form a reference beam and contains optical cops to provide the necessary configuration of the reference beam in recording information on the recording medium with perpendicular incidence of the reference beam on the surface of the recording medium, characterized in that the device is introduced turning mechanism of the recording medium relative to the recording head, and wherein the rotation axis coincides with the reference beam axis. 2. A device for recording multiplex holograms in an optical-holographic memory system, including a laser, a beam splitter, which divides the laser radiation into two parts, one of which is used to form the object beam and contains along the rays in front of the recording medium optical elements for expanding the radiation beam and a recording head As part of a matrix device for inputting recorded information and a Fourier transform lens, the other part is used to form a reference beam and contains optical copes to ensure the necessary configuration of the reference beam in the field of recording information on the recording medium with a perpendicular incidence of the reference beam on the surface of the recording medium, characterized in that the recording head is multi-channel with the number of channels corresponding to the number of subholograms in the multiplex hologram when they are concentric relative to the axis of the reference beam .