KR100288480B1 - Holographic data storage / playback device and method - Google Patents

Abstract

The present invention relates to a system and method for holographic data storage and reproducing, and more particularly, to a system and method for holographic data storage and reproducing for simultaneously recording two pages.

According to the present invention, the light splitter 120 separates the light from the light source 110 into the first and second object light, the first mirror 130 to change the direction of the first object light, and the direction of the second object light. The second mirror 140 for changing the light, the first and second reference parts R1 and R2 for passing all light through the two pages to be recorded, and the first and second signal parts for inputting the data to be recorded. The first object incident from the first mirror 130 on one surface composed of the microprocessor 200 and the first reference unit R1 and the first signal unit S1 respectively divided into (S1, S2) and outputted. The second surface of the first SLM 150, the second reference part R2, and the second signal part S2 is input to the second object light incident from the second mirror 140. The first and second object light incident from the second SLM 160 and the first and second SLMs 150 and 160 are simultaneously recorded with each other as the reference light, and the first and second objects are simultaneously recorded. The storage medium 170 for reproducing the second and first object light, respectively, in response to the incidence of the first and second and second CCDs for restoring the first and second reproduction light reproduced in the storage medium 170 to electrical signals. Detecting reproduction data by cutting the first and second reference portions R1 and R2 from the 180 and 190 and the first and second reproduction light reproduced by the first and second CCDs 180 and 190. It consists of a signal processing unit 210 for.

Therefore, the present invention can record two surfaces at the same time, there is an effect that can reduce the recording time when recording a large number of surfaces.

Description

HOLOGRAPHIC DATA STORAGE SYSTEM AND METHOD

The present invention relates to a system and method for holographic data storage and reproducing, and more particularly, to a system and method for holographic data storage and reproducing for simultaneously recording two pages.

In general, a holographic data storage system aims to record object light from an object and later reproduce it.

Holographic data recording is achieved by recording the intensity and direction of the object light reflected from the object. The intensity and direction of the light of the object is composed of the interference between the object light and the reference light to form an interference fringe, and the interference fringe is formed in a cube, that is, a storage crystal, made of a material that responds to the intensity of the interference fringe. When the reference light is irradiated to the recorded interference fringe, the hologram, which is a three-dimensional image of the object, is reproduced.

At this time, the hologram data recorded in the storage crystal can only be read by the reference light used in the recording process, and the hologram data recorded in the storage crystal can not be read by the reference light having a different wavelength or phase from the reference light used in the recording process. Done.

By using this hologram property, it is possible to store a large amount of data in a small cube by recording a lot of hologram data in the same place of the storage material cube with different reference light.

As shown in FIG. 1, a general holographic data storage system is installed at a position corresponding to a coherent beam required for holography, that is, a light source 10 for generating a laser light, and a light source 10. Beam splitter 20 for separating the coherent light generated from the light into a reference beam and a signal beam, that is, an object beam, and a mirror positioned on an optical path of the reference beam and changing the direction of the reference beam. 30, a mirror 40 for changing the direction of the object light, and input data, that is, binary data of a plurality of pixels configured in units of pages, are placed on the optical path of the object light reflected from the mirror 40. Spatial light modulator (SLM: SLM) (50), the object light output from the SLM 50 and the reference light reflected from the mirror 30 is located on the optical path cross each other The object light and the reference light A storage medium 60 for recording the interference fringe generated by the interference of the light source and restoring the interference fringe recorded by the irradiation of the reference light, and positioned on the optical path of the interference fringe generated when the storage medium 60 is irradiated with the reference light; It consists of a CCD (Charge Coupled Device) 70 for converting the interference fringe recorded in the storage medium 60 to convert it into an original electrical signal.

The operation of the general holographic data storage system configured as described above will be described.

The irradiated light source 10 is divided into a reference light and an object light in the optical separator 20.

In this case, the object light is inputted to the spatial light modulator 50 and modulated by the mirror 40 in a 90 ° direction. That is, the object light is modulated in units of one page of binary data of light and shade of actual pixels of the data input from the spatial light modulator 50. The object light modulated by the SLM 50 is incident on the storage medium 60.

In addition, the reference light is changed in direction by the rotating mirror 30 and is incident to the storage medium 60.

The object light and the reference light cause interference inside the storage medium 60 for recording the hologram, and light-induced generation of mobile charge of the internal kinetic charge of the storage medium 60 according to the intensity of the interference fringes generated at this time. ) And the interference fringe is recorded through this process.

At this time, angle overlap and spatial overlap are used to record a large amount of data in the storage medium 60.

The angular superposition is to record while changing the incident angle of the reference light in units of pages by rotating the mirror 30, the spatial superimposition is to divide and record the storage medium in a predetermined size.

However, since the conventional hologram data storage system records only one object light on one surface at a time, a time-consuming time is required for recording.

That is, since only one side of the data is recorded after adjusting the angle of incidence of the reference light by adjusting the angle of rotation of the mirror 30 by using the angle overlap, there is a problem in that it takes a lot of recording time when recording many surfaces.

SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide a holographic data storage system and method for dividing input data into a reference portion and a signal portion and enabling simultaneous recording using two SLMs.

The present invention for achieving the above object is an optical separator for separating the light from the light source into the first and second object light, a first mirror for changing the direction of the first object light, to change the direction of the second object light A second processor, a microprocessor for dividing the two pages (page) to be recorded into first and second reference parts through which all light passes and the first and second signal parts into which data to be recorded are input, respectively, and outputting the first reference The second mirror 140 includes a first SLM for inputting one surface of the first and second signal parts to the first object light incident from the first mirror, and the other surface of the second reference part and the second signal part. The second SLM 160 and the first and second object light incident from the first and second SLMs 150 and 160 are simultaneously inputted as reference light, The first and second object light according to the incidence of the second and second A storage medium for reproducing the first object light, respectively, first and second CCDs for restoring the first and second reproduction lights reproduced from the storage medium into electrical signals, and a second and second CCDs reproduced in the first and second CCDs; Provided is a holographic data storage / reproducing system using spatial superimposition, characterized in that it comprises a signal processing section for detecting playback data by cutting the first and second reference portions from the first and second reproduction lights.

Also, the present invention divides two pages to be recorded into first and second reference parts through which all light passes and first and second signal parts including data to be recorded, respectively, to form input data, respectively. A setting step, a data input step of inputting input data of two surfaces set as the first and second reference parts and the first and second signal parts to respective object lights, and using the object light with the data input thereto as reference light Simultaneous recording step of recording on the storage medium at the same time, the first or second portion consisting of the first reference portion and the signal portion or the second reference portion and the signal portion by selecting the signal portion to be reproduced and incident the corresponding second or first object light And a cutting step of cutting the first and second reference portions of the reproduced first and second object lights, and a cutting step of regenerating the object light. The.

1 is a block diagram of a typical holographic data storage system

2 is a block diagram of a holographic data storage / playback system according to the present invention

3 is a structural diagram of input data according to the present invention;

4 is a diagram showing a state recorded in a storage medium according to the present invention;

5 and 6 are views for explaining the reproduction process according to the present invention

7 is a flowchart illustrating a recording process of the holographic data storing / reproducing method according to the present invention.

8 is a flowchart illustrating a reproduction process of the holographic data storage / reproduction method according to the present invention.

Explanation of symbols on the main parts of the drawings

110: light source 120: optical separator

130, 140: Mirror 150, 160: SLM

170: storage medium 180, 190: CCD

200: microprocessor 210: signal processing unit

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 2, the holographic data storage / reproducing system according to the present invention includes a light source 110, an optical splitter 120, mirrors 130 and 140, two SLMs 150 and 160, and a storage medium 170. ), Two CCDs 180 and 190, a microprocessor 200, and a signal processor 210.

The optical splitter 120 splits the light introduced from the light source 110 into first and second object light.

The mirror 130 changes the direction of the first object light to enter the first SLM 150, and the mirror 140 changes the direction of the second object light to enter the second SLM 160. It is to let.

The microprocessor 200 may include the first and second reference units R1 and R2 for passing all light through two pages to be recorded, and the first and second signal units S1 for inputting data to be recorded. The output is divided into S2).

That is, as shown in FIG. 3, the signal part S including data to be recorded and the reference part R functioning as reference light by passing all the light are respectively formed as one surface to make two surfaces.

In other words, one surface is formed of the first reference portion R1 and the second reference portion S1, and the other surface is formed of the second reference portions R2 and S2. In this case, the reference units R1 and R2 occupy a smaller area than the signal units S1 and S2.

Here, the boundary parts T1 and T2 through which all light does not pass are formed between the first and second reference parts R1 and R2 and the first and second signal parts S1 and S2. That is, the boundary portion T1 is formed between the first reference portion R1 and the first signal portion S1 so as not to pass all the light, and between the second reference portion R2 and the second signal portion S2. The boundary part T2 which does not let light pass is formed.

The first SLM 150 receives a first object incident from the mirror 130 on one surface formed of the first reference part R1 and the first signal part S1 under the control of the microprocessor 200. The second SLM 160 inputs light to the second mirror (R2) and the other surface formed of the second reference unit R2 and the second signal unit S2 under the control of the microprocessor 200. Input to the second object light incident at 140.

The storage medium 170 simultaneously records the first and second object light incident from the first and second SLMs 150 and 160 as reference light, and sets the first and second object light according to the incident of the first and second object light. To reproduce the second and the first object light, respectively.

The first and second CCDs 180 and 190 restore the first and second reproduction lights reproduced from the storage medium 170 to electrical signals.

The signal processor 210 cuts the first and second reference units R1 and R2 from the first and second reproduction lights reproduced by the first and second CCDs 180 and 190 to detect the reproduction data. It is for.

The operation of the holographic data storage / reproduction system according to the present invention configured as described above will be described.

First, the case where data is recorded in the storage medium 170 will be described.

The light source 110 is operated and the light emitted from the light source 110 is divided into the first and second object light in the optical separator 120.

As described above, the first and second object lights divided by the optical separator 120 are changed to 90 ° by the mirrors 130 and 140 and are incident to the first and second SLMs 150 and 160, respectively.

Meanwhile, as shown in FIG. 3, the microprocessor 200 is divided into a reference part R and a signal part S, and has a boundary part T at a boundary thereof. At this time, the reference unit R1 allows all the light to pass through, and puts data to be recorded in the signal unit S, and the boundary unit T forms two pages to prevent all the light from passing through.

That is, in the microprocessor 200, a first reference unit R1 through which all light passes, a first signal unit S1 including data to be recorded, the first reference unit R1, and a first signal unit S1. The first surface formed by the boundary portion T1 that does not pass all the light to indicate the boundary of the (), the second reference portion R2 that passes all the light, and the second signal portion S2 containing the data to be recorded, In order to indicate the boundary between the second reference portion R2 and the second signal portion S2, a second surface formed of a boundary portion T2 that does not pass all light is made, and the first and second SLMs 150 are respectively formed. , 160).

That is, the microprocessor 200 inputs a first surface to the first SLM 150 and a second surface to the second SLM 160.

As described above, the first and second surfaces input to the first and second SLMs 150 and 160 are simultaneously incident and recorded on the storage medium 170 by the first and second object light.

That is, as shown in FIG. 4, the first object light including the first reference part R1 and the first signal part S1 is stored in the storage medium 170 by the second object light incident from the second SLM 160. ), And the second object light including the second reference part R2 and the second signal part S2 is recorded in the storage medium 170 by the first object light incident from the first SLM 150. .

Therefore, the data recorded on one page of the storage medium 170 may include the first and second reference units R1R2, the first reference unit and the second signal unit R1S2, and the second reference unit as shown in FIG. 4. A diffraction grating consisting of the first signal part R2S1 and the first and second signal parts S1S2 is formed.

As described above, the case of reproducing in a state where two surfaces are recorded simultaneously is as follows.

First, a process of reproducing the second object light by inputting the first object light will be described with reference to FIG. 5.

When the light incident on the light source 110 is separated by the optical separator 120 and divided into the first and second object light, the second object light is not incident to the mirror 140 by a shutter (not shown). Only one object light is redirected through the mirror 130 and then enters the storage medium 170 through the first SLM 150.

In this case, the first object light is the same as the first reference part R1 as the reference light. That is, since the reference units R1 and R2 pass all the light, the incident first object light becomes the same as the first reference unit R1.

As described above, the second reference unit R2 and the second signal unit S2 are output as reproduction light in the storage medium 170 by the first reference unit R1 of the incident first object light. Will be incident on.

As shown in FIG. 5, the reconstructed light including the second reference unit R2 and the second signal unit S2 is cut at the left side of the signal processing unit 210 about the boundary portion T2, so that the second signal unit S2 is cut. ) Only.

Next, a process of reproducing the first object light by inputting the second object light will be described with reference to FIG. 6.

When the light incident on the light source 110 is separated by the optical separator 120 and divided into the first and second object light, the first object light is not incident to the mirror 130 by a shutter (not shown). Only two object lights are incident on the storage medium 170 through the second SLM 160 after the direction is changed through the mirror 140.

In this case, the second object light is the same as the second reference part R2 as the reference light. That is, since the reference units R1 and R2 pass all the light, the incident second object light becomes the same as the second reference unit R2.

As described above, the first reference unit R1 and the first signal unit S1 are output as reproduction light in the storage medium 170 by the second reference unit R2 of the incident second object light. Will be incident on.

As shown in FIG. 6, the reconstructed light including the first reference unit R1 and the first signal unit S1 is cut at the left side of the signal processing unit 210 about the boundary T1, so that the first signal unit S1 is cut. ) Only.

As described above, since the holographic data storage / reproducing system of the present invention operates, two surfaces can be recorded at the same time.

In addition, in the holographic data storage / reproduction method according to the present invention, the input data setting step 200, the data input steps 210 and 220, the simultaneous recording step 230, and the reproduction step are shown in FIGS. 7 and 8. 300, 310, 320, 330, 340, and the cutting step 350.

The input data setting step 200 includes first and second reference units R1 and R2 for passing all the lights through two pages to be recorded, and first and second signal units including data to be recorded. It is a step of forming input data by dividing into S1 and S2, respectively.

Here, the boundary parts T1 and T2 through which all light does not pass are formed between the first and second reference parts R1 and R2 and the first and second signal parts S1 and S2.

The data input step 210 or 220 inputs input data of two surfaces set to the first and second reference units R1 and R2 and the first and second signal units S1 and S2 to respective object lights. This is the step.

The simultaneous recording step 230 is a step of simultaneously recording to the storage medium by using the object light of the data input to each other as a reference light.

In the reproducing steps 300, 310, 320, 330, and 340, the first reference unit R1 and the signal unit may be selected by selecting the signal units S1 and S2 to be reproduced and incident a corresponding second or first object light. It is a step of reproducing the first or second object light composed of S1 or the second reference part R2 and the signal part S2.

The cutting step 350 is a step of cutting the first and second reference parts R1 and R2 of the reproduced first and second object lights.

The holographic data storing / reproducing method according to the present invention performed as described above will be described in detail.

First, as shown in FIG. 3, the first and second reference parts R1 and R2 passing through all the light and the data to be recorded are performed by performing the input data setting step 200. Each of the first and second signal units S1 and S2 including the input data is formed.

In this case, in order to facilitate cutting, boundary parts T1 and T2 through which all light does not pass are formed between the first and second reference parts R1 and R2 and the first and second signal parts S1 and S2. do.

After performing the input data setting step as described above, the data input steps 210 and 220 are performed to set the first and second reference parts R1 and R2 and the first and second signal parts S1 and S2. Input data of two sides is input to each object light.

After inputting the respective input data to the SLM in this manner, the simultaneous recording step 230 is performed, and as shown in FIG.

In this manner, after the two surfaces of the first and second reference units R1 and R2 and the first and second signal units S1 and S2 are simultaneously recorded on the storage medium, the playback step is performed.

In the reproducing steps 300, 310, 320, 330, and 340, the first reference unit R1 and the signal unit are selected by selecting the signal units S1 and S2 to be reproduced and incident the corresponding second or first object light. The first or second object light composed of S1 or the second reference portion R2 and the signal portion S2 is reproduced.

In other words, one signal S1 or S2 to be reproduced is selected (300).

In this case, when the reproduction of the first signal unit S1 is desired, the second object light is incident (310) to reproduce the first reference unit R1 and the first signal unit S1 (320). Since the boundary portion T1 is formed between the reproduced first reference portion R1 and the first signal portion S1, only the desired first signal portion S1 is output when the reference portion is cut (350).

In addition, when the second signal unit S2 is desired to be reproduced, the first object light is incident (330) to reproduce the second reference unit R2 and the second signal unit S2 (340). Since the boundary portion T2 is formed between the reproduced second reference portion R2 and the second signal portion S2, only the desired second signal portion S2 is output when the reference portion is cut (350).

As described above, the holographic data storage / reproducing system according to the present invention can record two surfaces at the same time, thereby reducing the recording time when recording many surfaces.

Claims (2)

An optical separator 120 that separates the light introduced from the light source 110 into first and second object light; A first mirror 130 for changing a direction of the first object light; A second mirror 140 for changing a direction of the second object light; First and second reference parts R1 and R2 through which all the two pages (Page) to be written pass through, and first and second signal parts (S1 and S2) into which data to be recorded are input, and the first and second reference parts (R1 and R2). A microprocessor 200 which divides and outputs the boundary parts T1 and T2 through which all light does not pass between the second reference parts R1 and R2 and the first and second signal parts S1 and S2, respectively; A first SLM (150) for inputting a surface composed of the first reference unit (R1) and the first signal unit (S1) to the first object light incident from the first mirror (130); A second SLM (160) for inputting the other surface of the second reference unit (R2) and the second signal unit (S2) to the second object light incident from the second mirror (140); The first and second object lights incident from the first and second SLMs 150 and 160 are simultaneously recorded as reference lights, and the second and first object lights are generated according to the incidence of the first and second object lights. A storage medium 170 for playing each; First and second CCDs 180 and 190 for restoring the first and second reproduction light reproduced in the storage medium 170 into electrical signals; And The first and second reference units R1 and R2 are cut from the first and second reproduction lights reproduced by the first and second CCDs 180 and 190 to the signal processor 210 for detecting the reproduction data. Holographic data storage / playback system using spatial superposition, characterized in that the configuration. First and second reference parts R1 and R2 for passing all light through two pages to be recorded, first and second signal parts S1 and S2 including data to be recorded, and the first and second pages. An input data setting step of forming input data, respectively, by dividing each of the second reference parts R1 and R2 and the first and second signal parts S1 and S2 into boundary parts T1 and T2 through which no light passes. 200; A data input step (210, 220) of inputting input data of two surfaces set to the first and second reference units (R1 and R2) and the first and second signal units (S1 and S2) to respective object lights; A simultaneous recording step (230) of simultaneously recording on the storage medium using the object light to which the data is input as reference light; Selecting the signal parts S1 and S2 to be reproduced and injecting the corresponding second or first object light, the first reference part R1 and the signal part S1 or the second reference part R2 and the signal part ( A reproduction step (300, 310, 320, 330, 340) of reproducing the first or second object light composed of S2); And And a cutting step (350) for cutting the first and second reference portions (R1, R2) of the reproduced first and second object lights.