KR20130018473A - Apparatus and method for recording micro-hologram - Google Patents

Abstract

PURPOSE: A microhologram recording device and a method are provided to record a microhologram by a coherent light source and supply insufficient exposure energy by a non-coherent light source. CONSTITUTION: A first light source(101) emits first light of coherence. First light systems(105-110) divide the first light into a signal beam and a reference beam. The first light systems provide the signal beam and the reference beam in the same location on each hologram recording medium(150). A second light source(111) emits second light of incoherence. A second light system(112) provides the second light to the same location on the hologram recording medium.

Description

Apparatus and method for recording micro-hologram

The disclosed embodiments relate to an apparatus and method for recording micro holograms, and more particularly, to a micro hologram recording apparatus and method capable of reducing power consumption during micro hologram recording and at the same time improving the quality of the recorded hologram image. It is about.

Hologram technology is a technology that can reproduce the signal as a stereoscopic image by recording the interference pattern between the signal beam and the reference beam containing the signal. Hologram technology can be used in various fields such as recording and reproducing stereoscopic images, preventing forgery and authenticity, and recording and reproducing digital data. In addition, micro-hologram technology has been commercialized by recording fine interference fringes on a flat plate-type photosensitive recording film in pixel units so that three-dimensional images can be viewed on a two-dimensional plane.

Micro holograms include rear projection micro holograms and reflective micro holograms. The rear projection type micro hologram is a method in which light transmitted through a recording film contains a stereoscopic image, and the reflective type micro hologram is a method in which light reflected from the recording film contains a stereoscopic image. In particular, the reflective micro-hologram can record / play back images with full-color and full-parallax, and can display gradations.

Micro-hologram recording is generally performed by dividing a beam emitted from the same light source to make a signal beam and a reference beam, optically modulating the signal beam, and then irradiating the signal beam and the reference beam at the same position on the photosensitive recording film. Can be performed. The modulation of the signal beam may be performed by a spatial light modulator, for example, in accordance with a computer-generated interference pattern based on the image to be finally reproduced from the photosensitive recording film.

In recording such micro holograms, the exposure energy applied to the photosensitive recording film is a very important factor. The exposure energy can be determined by the intensity and the exposure time of light irradiated on the photosensitive recording film. In order to improve the quality of the image to be reproduced, appropriate exposure energy needs to be provided to the photosensitive recording film. When the output of the laser used as the light source is weak, the exposure time increases, and thus, the time required for recording the micro hologram may increase, and may also be sensitive to the external environment such as vibration during recording. In addition, the laser with high output power can increase the manufacturing cost of the micro hologram recording device, and can also increase the power consumption.

Provided are a micro hologram recording apparatus and method capable of reducing power consumption during micro hologram recording and improving the quality of a recorded hologram image.

According to one type of the present invention, there is provided an apparatus, comprising: a first light source for emitting a coherent first light; A first optical system for dividing the first light into a signal beam and a reference beam to modulate the signal beam, and providing the signal beam and the reference beam at the same position on the hologram recording medium, respectively; A second light source emitting a second non-coherent light that does not interfere with the signal beam and the reference beam; And a second optical system for simultaneously providing the second light at the same position as the signal beam and the reference beam on the hologram recording medium.

The micro hologram recording apparatus includes: a substrate on which a hologram recording medium on which an image is to be recorded is mounted; And a positioning device for moving the substrate in accordance with the recording position on the hologram recording medium.

The first optical system may include: a first beam splitter for dividing light emitted from the first light source into a signal beam and a reference beam; A signal beam transmitter for modulating the signal beam and providing the signal beam to a hologram recording medium; And a reference beam transfer unit for providing the reference beam at the same position as the signal beam on the hologram recording medium.

According to one embodiment, the signal beam transmission unit, a beam extender for extending the beam diameter of the signal beam coming from the first beam splitter; A spatial light modulator for modulating the extended signal beam according to an image to be recorded on a hologram recording medium to load image information on the signal beam; Fourier transform optical system for Fourier transform the signal beam carrying the image information to focus on the hologram recording medium; And a second beam splitter configured to transfer the signal beam from the beam expander to the spatial light modulator and to transmit the signal beam reflected from the spatial light modulator to the Fourier transform optical system.

In addition, the reference beam transfer unit may include at least two mirrors.

The reference beam transfer unit may be configured such that the cross-sectional area of the reference beam matches the cross-sectional area of the signal beam on the hologram recording medium.

For example, the spatial light modulator may be a reflective spatial light modulator.

According to one embodiment, the second optical system includes at least one mirror that reflects the second light toward the hologram recording medium, wherein the second optical system has a path where the second light differs from the reference beam and the signal beam. It can be configured to proceed along.

In another embodiment, the second optical system includes a mirror that reflects the second light toward the first beamsplitter, wherein the second optical system divides the second light into a path of a reference beam and a path of a signal beam. The reference beam transmitter and the signal beam transmitter may be shared to proceed.

In yet another embodiment, the second optical system includes a third beamsplitter disposed on a path of a reference beam between the first beamsplitter and the hologram recording medium, wherein the second optical system is configured such that the second light is a reference beam. The reference beam transfer unit may be shared to proceed along the path of.

Here, the second light source may be disposed to face the third beam splitter.

In another embodiment, the second optical system includes a fourth beamsplitter disposed between the first beamsplitter and the beam expander, and a mirror that reflects the second light toward the fourth beamsplitter, wherein The second optical system may share the signal beam transfer unit so that the second light travels along the path of the signal beam.

According to one embodiment, the signal beam transmission unit, a beam extender for extending the beam diameter of the signal beam coming from the first beam splitter; A transmissive spatial light modulator for modulating the extended signal beam according to an image to be recorded on a hologram recording medium to load image information on the signal beam; Fourier transform optical system for Fourier transform the signal beam carrying the image information to focus on the hologram recording medium; And a mirror reflecting the signal beam from the beam expander to the transmissive spatial light modulator.

For example, the second light source may be a laser or a light emitting diode (LED) that emits light that does not interfere with the signal beam and the reference beam.

In addition, the hologram recording medium includes a recording layer and a protective layer coated on a surface of the recording layer to protect the recording layer, wherein the second light source has a spatial interference length of the second light of 2 times the thickness of the protective layer. It may be configured to be smaller than twice.

According to one embodiment, when the exposure energy corresponding to the lower limit of the linear recording section of the hologram recording medium is called E1, and the exposure energy corresponding to the upper limit of the linear recording section of the hologram recording medium is referred to as E2, the second light source is The exposure energy of E1 may be configured to be applied to the hologram recording medium, and the first light source may be configured to apply exposure energy of 0 to (E2-E1) to the hologram recording medium.

On the other hand, according to another type of the invention, the step of dividing the coherent first light into a signal beam and a reference beam; Loading image information on the signal beam; Providing each of the reference beam and the signal beam carrying the image information at the same position on the hologram recording medium; And simultaneously providing a non-coherent second light that does not interfere with the signal beam and the reference beam at the same position as the signal beam and the reference beam on the hologram recording medium.

Here, the coherent first light may be emitted from a first light source, and the non-coherent second light may be emitted from a second light source that is independent of the first light source.

The micro hologram recording apparatus according to the disclosed embodiments can compensate for the insufficient exposure energy with the non-coherent light source while recording the micro hologram with the coherent light source whose output is relatively small. Therefore, the output of the coherent light source required to record the micro hologram can be lowered. Since insufficient exposure energy can be supplemented with a relatively inexpensive incoherent light source, the manufacturing cost of the micro hologram recording device can be lowered, and the power consumption can also be lowered. In addition, according to the disclosed embodiments, since the grayscale of the holographic image to be reproduced using two light sources can be accurately represented, the quality of the holographic image can be improved.

1 schematically shows an exemplary structure of a micro hologram recording device according to one embodiment.
FIG. 2 is a sectional view showing the hologram recording medium portion shown in FIG. 1 in more detail.
3 is a graph showing a diffraction efficiency curve with respect to exposure energy in a hologram recording medium when no additional incoherent light source is used in the micro hologram recording device shown in FIG.
4 is a graph showing a diffraction efficiency curve with respect to exposure energy in a hologram recording medium when an additional incoherent light source is used in the micro hologram recording apparatus shown in FIG.
5 schematically shows an exemplary structure of a micro hologram recording device according to another embodiment.
6 schematically shows an exemplary structure of a micro hologram recording device according to another embodiment.
7 schematically shows an exemplary structure of a micro hologram recording apparatus according to another embodiment.
8 schematically shows an exemplary structure of a micro hologram recording device according to another embodiment.

Hereinafter, a micro hologram recording apparatus and method will be described in detail with reference to the accompanying drawings. In the following drawings, like reference numerals refer to like elements, and the size of each element in the drawings may be exaggerated for clarity and convenience of explanation.

1 schematically shows an exemplary structure of a micro hologram recording apparatus according to one embodiment. Referring to FIG. 1, the micro-hologram recording apparatus 100 according to the present embodiment refers to a first light source 101 that emits coherent light, and reference the coherent light emitted from the first light source 101 to a signal beam. Splitting the beam into modulated signal beams, and emitting a first optical system that provides the signal and reference beams at the same position on the hologram recording medium 150, respectively, and the non-coherent light that does not interfere with the signal and reference beams. And a second optical system for providing the non-coherent light on the hologram recording medium 150. In addition, the micro-hologram recording apparatus 100 moves the substrate 120 according to the substrate 120 on which the hologram recording medium 150 on which an image is to be recorded is mounted, and the recording position on the hologram recording medium 150. The apparatus 121 may further include.

Here, the first light source 101 may include, for example, a laser capable of emitting coherent light. In addition, the first light source 101 may further include not only a laser, but also suitable additional devices capable of adjusting the intensity of the output light, for example, the waveform (eg, continuous wave, pulse wave) and period of the output light. have.

The first optical system includes a first beam splitter 103 for dividing the light emitted from the first light source 101 into a signal beam and a reference beam, a signal beam transfer unit for modulating the signal beam and providing it to the hologram recording medium 150; And a reference beam transfer unit for providing the reference beam to the hologram recording medium 150. The first beamsplitter 103 may for example be simply a transflective mirror. In this case, the first beam splitter 103 may transmit approximately 50% of the incident light to the signal beam transmission unit, and reflect the approximately 50% of the incident light to the reference beam transmission unit. However, this is merely an example, and the distribution ratio of the signal beam and the reference beam may be set differently according to the embodiment. In addition, the first optical system may further include a filter 102 disposed between the first light source 101 and the first beam splitter 103. The filter 102 may transmit only light having a wavelength of a specific band, for example, as a bandpass filter.

The signal beam transmitting unit modulates the signal beam according to an image to be recorded on the beam extender 105 and the hologram recording medium 150 to enlarge the beam diameter of the signal beam, and a spatial light modulator for loading the image information on the signal beam. a light modulator (SLM) 107, which transmits the signal beam incident from the beam expander 105 to the spatial light modulator 107, and transmits the signal beam reflected from the spatial light modulator 107 to the hologram recording medium 150. A second beam splitter 106 and a Fourier transformation optical system 108 for Fourier transforming the signal beam carrying the image information and focusing the hologram recording medium 150 may be included.

The beam expander 105 may extend the signal beam to a size corresponding to the effective light modulation area of the spatial light modulator 107, for example, and may be formed of a plurality of optical elements including a refractive lens. The second beam splitter 106 transmits the extended signal beam to the spatial light modulator 107, for example, and reflects the signal beam reflected from the spatial light modulator 107 to perform the Fourier transform optical system 108. Can be provided to However, this is merely an example, and in other embodiments, the second beamsplitter 106 is configured to reflect the extended signal beam to the spatial light modulator 107 and transmit the signal beam reflected by the spatial light modulator 107. May be configured. In this case, the spatial light modulator 107 may be disposed above the second beam splitter 106 in the drawing. In one example, the second beamsplitter 106 may simply be a transflective mirror that reflects a portion of incident light and transmits the remaining portion. In another example, the second beamsplitter 106 may be a polarizing beamsplitter that transmits or reflects light depending on the polarization direction of the incident light. In this case, a polarizer 104 may be disposed between the first beam splitter 103 and the second beam splitter 106 to transmit only light in a specific polarization direction. Also, although not shown, a quarter wave plate may be further disposed between the second beam splitter 106 and the spatial light modulator 107.

The reference beam transfer unit serves to transfer the reference beam split by the first beam splitter 103 onto the hologram recording medium 150. In FIG. 1, simply two mirrors 109 and 110 are shown as reference beam transfer units. However, the actual reference beam transfer unit may be more complicated. For example, the mirrors 109 and 110 can be configured to be rotatable and movable so that the reference beam can be incident at a desired position on the hologram recording medium 150 at a desired angle of incidence. In particular, the reference beam transfer section can be configured such that the reference beam is incident at the same position on the hologram recording medium 150 as the signal beam. In addition, the reference beam transfer unit may be configured to match the cross-sectional area of the reference beam and the signal beam on the hologram recording medium 150.

In the above-described micro hologram recording apparatus 100, the signal beam transmitted through the first beam splitter 103 is optically modulated by the spatial light modulator 107 and then the hologram recording medium 150 by the Fourier transform optical system 108. ) Can be focused over. The reference beam reflected by the first beam splitter 103 is reflected by the mirrors 109 and 110, and then passes through the substrate 120 and enters the hologram recording medium 150 below. Thereafter, the signal beam and the reference beam meet in the hologram recording medium 150, where an interference pattern generated while the signal beam and the reference beam interfere with each other can be recorded on the hologram recording medium 150. Although FIG. 1 shows that the light transmitted through the first beamsplitter 103 becomes the signal beam and the light reflected from the first beamsplitter 103 becomes the reference beam, this is only one example. For example, in another embodiment, the micro hologram recording apparatus 100 is configured such that the light transmitted through the first beam splitter 103 becomes a reference beam and the light reflected from the first beam splitter 103 becomes a signal beam. May be

On the other hand, according to this embodiment, in order to further improve the recording efficiency for the hologram recording medium 150, additional light may be further irradiated to the hologram recording medium 150. The second light source 111 independent of the first light source 101 serves to provide this additional light to the hologram recording medium 150. There is no particular limitation on the type of the second light source 111. For example, the second light source 111 may be a laser or a light emitting diode (LED) may be used. When the second light source 111 is a laser, the second light source 111 may emit light of a wavelength different from that of the first light source 101, or may emit light of the same wavelength having low spatial coherence. You may. In addition, when the second light source 111 is an LED, it may emit light having a spectral band that does not include the wavelength of the first light source 101, or a spectral band that includes the wavelength of the first light source 101. It may emit light having That is, as long as the light emitted from the second light source 111 does not interfere with the signal beam and the reference beam, any light source may be used.

The second optical system serves to provide the light emitted from the second light source 111 on the hologram recording medium 150. 1 shows one mirror 112 as a second optical system. However, the actual second optical system may be more complicated. For example, the second optical system may be composed of a plurality of mirrors and lenses, and the mirror (so that the light emitted from the second light source 111 can be incident on a desired position on the hologram recording medium 150 at a desired angle of incidence). 112 may be configured to be rotatable and movable. In particular, the second optical system may be configured such that the light emitted from the second light source 111 is incident on the same position on the hologram recording medium 150 as the reference beam and the signal beam. In this embodiment, the light emitted from the second light source 111 is reflected by the mirror 112 and then passes through the substrate 120 and enters the hologram recording medium 150 below.

Meanwhile, referring to FIG. 2, the hologram recording medium 150 may include a recording layer 151 made of a photosensitive material and a protective layer coated on the surface of the recording layer 151 to protect the recording layer 151. 152). As shown in FIG. 2, a part of the light emitted from the second light source 111 completely passes through the substrate 120 and the recording layer 151, and is then reflected by the protective layer 152 to again record the recording layer 151. Can be entered into. In this case, interference may occur between the light reflected by the protective layer 152 and the light passing through the recording layer 151. The interference thus generated may affect the interference fringe between the signal beam and the reference beam recorded in the recording layer 151. Therefore, in order to prevent the occurrence of such interference, the second light source 111 may be configured such that the spatial coherence length of the emitted light is less than twice the thickness of the protective layer 152.

By using such an additional second light source 111, the recording efficiency for the hologram recording medium 150 can be improved. 3 and 4 are graphs for showing the effect of using the second light source 111. First, FIG. 3 is a graph showing a diffraction efficiency curve with respect to exposure energy in the hologram recording medium 150 when the additional non-coherent second light source 111 is not used in the micro hologram recording apparatus 100. 4 is a graph showing a diffraction efficiency curve with respect to the exposure energy of the hologram recording medium 150 when the second light source 111 is used in the micro hologram recording apparatus 100.

Referring to FIG. 3, when the second light source 111 is not used, almost no photosensitive action occurs in the hologram recording medium 150 when the exposure energy due to the light emitted from the first light source 101 is less than E0. When the exposure energy between E0 and E1 is applied to the hologram recording medium 150, the diffraction efficiency due to the interference fringe recorded on the hologram recording medium 150 changes nonlinearly (hereinafter, between E0 and E1). The exposure energy section is defined as a 'first nonlinear recording section'. Also, when the exposure energy between E1 and E2 is applied to the hologram recording medium 150, the diffraction efficiency increases linearly in proportion to the exposure energy (hereinafter, the exposure energy section between E1 and E2 is referred to as the 'linear recording section'. '). Then, in the exposure energy between E2 and ES, the diffraction efficiency changes nonlinearly (hereinafter, the exposure energy section between E2 and ES is defined as the 'second nonlinear recording section'). Finally, even if exposure energy of ES or more is applied, the diffraction efficiency no longer increases (hereinafter, the exposure energy section of ES or more is defined as a 'saturation section').

Therefore, when recording the interference fringe on the hologram recording medium 150, the exposure energy of the linear recording section (i.e. between E1 and E2) is applied to the hologram recording medium 150 in accordance with the gradation of the image to be reproduced later. For example, when the exposure energy of E1, which is the lower limit of the linear recording section, is applied, since the diffraction hardly occurs in the hologram recording medium 150, the brightness of the reproduced image is relatively bright, and the exposure energy of E2, which is the upper limit of the linear recording section, is When applied, diffraction occurs largely in the hologram recording medium 150, so that the brightness of the reproduced image is relatively dark. Therefore, by applying exposure energy between E1 and E2 in accordance with the gradation of the image to be reproduced, rich gradation expression is possible.

The exposure energy applied to the hologram recording medium 150 can generally be adjusted by controlling the light intensity and the exposure time. For example, when the first light source 101 emits a continuous wave, the desired exposure energy for adjusting the intensity of the emitted light or for adjusting the exposure time may be applied to the hologram recording medium 150. In addition, when the first light source 101 emits a pulse wave, it is possible to adjust the number of emission of the pulse wave or the intensity of the light. By the way, since the exposure energy of the E1 to E2 section should be applied to the hologram recording medium 150 without using the exposure energy of the 0 to E1 section, there is a waste of the exposure energy. In particular, in order to apply the exposure energy of E2, a high output laser having a relatively high price is used as the first light source 101. In addition, the exposure time may be long to obtain the desired exposure energy.

On the other hand, when the non-coherent second light source 111 is used together with the first light source 101, that is, the light emitted from the first light source 101 (that is, the signal beam and the reference beam) and the second light source 111 are used. When the light emitted by the light incident at the same time enters the hologram recording medium 150, the exposure energy provided by the first light source 101 can be reduced as shown in the graph of FIG. For example, when the second light source 111 provides the exposure energy of E1, the first light source 101 may apply the exposure energy of 0 to (E2-E1) to the hologram recording medium 150. . Therefore, a relatively low cost laser can be used as the first light source 101, and the exposure time can be shortened. In addition, even when the second light source 111 is used, since the slope of the diffraction efficiency curve does not change in a section in which the diffraction efficiency changes linearly, the gray scale expression power can be maintained as it is. When the sensitivity of the hologram recording medium 150 is increased to reduce the exposure energy and the exposure time, various gradients may become difficult while the slope of the diffraction efficiency curve increases rapidly, but such a problem does not occur in this embodiment. You may not.

In the embodiment shown in FIG. 1, the first optical system for the first light source 101 and the second optical system for the second light source 111 are completely separated, so that the light emitted from the first light source 101 and the second optical system are completely separated. The light emitted from the light source 111 travels in different paths. However, the micro hologram recording apparatus may be configured such that a part of the second optical system is coupled to the first optical system so that the light emitted from the second light source 111 travels with the signal beam and / or the reference beam. 5 to 7 show various embodiments of the micro hologram recording apparatus for this purpose.

First, in the embodiment shown in FIG. 5, the micro hologram recording apparatus 200 is configured such that the light emitted from the second light source 111 is divided into the paths of the signal beam and the reference beam, respectively. Referring to FIG. 5, the micro-hologram recording device 200 divides a first light source 101 emitting coherent light and a coherent light emitted from the first light source 101 into a signal beam and a reference beam. A first optical system that modulates the beam and provides a signal beam and a reference beam at the same location on the hologram recording medium 150, and a second light source 111 that emits non-coherent light that does not interfere with the signal and reference beams And a second optical system for providing the non-coherent light on the hologram recording medium 150. Here, the first light source 101 and the first optical system have the same configuration as described in FIG.

In the embodiment of FIG. 5, the light emitted from the second light source 111 does not enter the hologram recording medium 150 directly but enters the first beam splitter 103. For example, light emitted from the second light source 111 may be incident on another incident surface adjacent to one incident surface of the first beam splitter 103 to which the light emitted from the first light source 101 is incident. . The first beam splitter 103 has four planes, one of which is an incident plane to which light emitted from the first light source 101 is incident, and the other two planes are an exit plane from which transmitted light and reflected light are emitted, respectively. . Light emitted from the second light source 111 may be incident on the other surface of the first beam splitter 103. In FIG. 5, the mirror 112 is disposed between the first beam splitter 103 and the second light source 111, so that the light emitted from the second light source 111 is reflected by the mirror 112 and then the first beam. It is shown incident on splitter 103. However, this is only an example, and the second light source 111 may be disposed to directly face the first beam splitter 103. In this case, the second optical system may share the signal beam transmission unit and the reference beam transmission unit of the first optical system.

According to this embodiment, the light emitted from the second light source 111 is separated into two beams by the first beam splitter 103, and then the hologram recording medium along the signal beam transfer unit and the reference beam transfer unit respectively. 150). Since the second light source 111 is an incoherent light source, the interference fringes of the signal beam and the reference beam may not be affected by the light emitted from the second light source 111. In the case of this embodiment, the light emitted from the second light source 111 can be provided exactly at the same position on the hologram recording medium 150 as the signal beam and the reference beam.

6, the light emitted from the second light source 111 travels along the same path as that of the reference beam. Referring to FIG. 6, the micro-hologram recording device 300 includes a third beam splitter 113 disposed between the first beam splitter 103 and the first mirror 109 of the reference beam transfer unit as a second optical system. , The second light source 111 is disposed to face the third beam splitter 113. The first light source 101 and the first optical system of the micro hologram recording device 300 may have the same configuration as described with reference to FIG. 1. The third beam splitter 113 may be configured to transmit the reference beam reflected by the first beam splitter 103, reflect the light emitted from the second light source 111, and travel in the same path as the reference beam. For example, the third beamsplitter 113 may be a simple transflective mirror or a dichroic mirror that selectively reflects or transmits light depending on the wavelength of the incident light or the incident surface of the incident light. Although the third beamsplitter 113 is shown as being disposed between the first beamsplitter 103 and the first mirror 109 in FIG. 6, the third beamsplitter 113 is formed by the first beamsplitter ( It may be placed anywhere on the path of the reference beam between the 103 and the hologram recording medium 150. According to the present embodiment, the light emitted from the second light source 111 may travel along the same path as the reference beam and be provided on the hologram recording medium 150. In this case, the second optical system may share the reference beam transfer unit of the first optical system.

In addition, in the embodiment shown in FIG. 7, the light emitted from the second light source 111 travels along the same path as the signal beam. Referring to FIG. 7, the micro hologram recording apparatus 400 includes a fourth beam splitter 114 disposed between the first beam splitter 103 and the beam expander 105 of the signal beam transmission unit as a second optical system. If the polarizer 104 is disposed in front of the beam expander 105 based on the traveling direction of the light, the fourth beam splitter 114 may be disposed between the first beam splitter 103 and the polarizer 104. Although the second light source 111 may be disposed to directly face the fourth beam splitter 114, as shown in FIG. 7, the mirror 112 is disposed between the second light source 111 and the fourth beam splitter 114. ) May be further arranged. The first light source 101 and the first optical system of the micro hologram recording device 400 may have the same configuration as described with reference to FIG. 1. The fourth beam splitter 114 may be configured to transmit a signal beam transmitted through the first beam splitter 103, reflect light emitted from the second light source 111, and travel in the same path as the signal beam. For example, the fourth beamsplitter 114 may be a simple transflective mirror or a dichroic mirror that selectively reflects or transmits light depending on the wavelength of the incident light or the incident surface of the incident light. According to the present embodiment, the light emitted from the second light source 111 may travel along the same path as the signal beam and be provided on the hologram recording medium 150. In this case, the second optical system may share the signal beam transfer unit of the first optical system.

The above-described micro hologram recording apparatus 100, 200, 300, 400 uses a reflective spatial light modulator 107 that reflects modulated light, but a transmissive spatial light modulator that transmits modulated light may be used. 8 exemplarily shows a schematic structure of a micro hologram recording apparatus 500 using a transmissive spatial co-modulator. Referring to FIG. 8, the micro hologram recording apparatus 500 includes a simple mirror 115 instead of the second beamsplitter 106, and a reflective spatial light modulator between the mirror 115 and the Fourier transform optical system 108. Instead of 107, a transmissive spatial light modulator 116 is disposed. In the present embodiment, the polarizer 104 may not be used. Compared to the micro hologram recording device 100 shown in FIG. 1, the micro hologram recording device 500 shown in FIG. 8 has the polarizer 104 removed, and the mirror 115 instead of the second beam splitter 106. Is arranged, and there is a difference in that the spatial light modulator 116 is transmissive. The remaining configuration of the micro hologram recording device 500 may be the same as the micro hologram recording device 100 shown in FIG. The configuration of FIG. 8 using the transmissive spatial light modulator 116 can be equally applied to the micro hologram recording apparatus 200, 300, 400 shown in FIGS.

Thus far, exemplary embodiments of the micro hologram recording apparatus and method have been described and illustrated in the accompanying drawings in order to facilitate understanding of the present invention. However, it should be understood that such embodiments are merely illustrative of the invention and do not limit it. And it is to be understood that the invention is not limited to the details shown and described. This is because various other modifications may occur to those skilled in the art.

100, 200, 300, 400, 500 ..... micro hologram recording device
101, 111 ..... light source 102 ..... filter
103, 106, 113, 114 ..... beam splitter 104 ..... polarizing plate
105 ..... beam expander 107, 116 ..... spatial light modulator
108 ..... Fourier transform optics 109, 110, 112, 115 ..... mirror
120 ..... Substrate 121 ..... Positioner
150 ..... Hologram recording medium
152 ..... protective layer

Claims (20)

A first light source that emits coherent first light;
A first optical system for dividing the first light into a signal beam and a reference beam to modulate the signal beam, and providing the signal beam and the reference beam at the same position on the hologram recording medium, respectively;
A second light source emitting a second non-coherent light that does not interfere with the signal beam and the reference beam; And
And a second optical system for simultaneously providing the second light at the same position as the signal beam and the reference beam on the hologram recording medium. The method of claim 1,
A substrate on which a hologram recording medium on which an image is to be recorded is mounted; And
And a positioning device for moving the substrate in accordance with a recording position on the hologram recording medium. The method of claim 1,
The first optical system is:
A first beam splitter dividing the light emitted from the first light source into a signal beam and a reference beam;
A signal beam transmitter for modulating the signal beam and providing the signal beam to a hologram recording medium; And
And a reference beam transfer unit for providing the reference beam at the same position as the signal beam on the hologram recording medium. The method of claim 3, wherein
The signal beam transmission unit:
A beam expander extending a beam diameter of the signal beam coming from the first beam splitter;
A spatial light modulator for modulating the extended signal beam according to an image to be recorded on a hologram recording medium to load image information on the signal beam;
Fourier transform optical system for Fourier transform the signal beam carrying the image information to focus on the hologram recording medium; And
And a second beam splitter configured to transfer the signal beam from the beam expander to the spatial light modulator and to transmit the signal beam reflected from the spatial light modulator to the Fourier transform optical system. The method of claim 4, wherein
And the reference beam transfer unit comprises at least two mirrors. The method of claim 5, wherein
And the reference beam transfer unit is configured such that the cross-sectional area of the reference beam on the hologram recording medium matches the cross-sectional area of the signal beam. The method of claim 4, wherein
And said spatial light modulator is a reflective spatial light modulator. The method of claim 3, wherein
The second optical system includes at least one mirror that reflects the second light toward the hologram recording medium, wherein the second optical system is micro-configured so that the second light travels along a different path from the reference beam and the signal beam. Hologram recording device. The method of claim 3, wherein
The second optical system includes a mirror that reflects the second light toward the first beamsplitter, wherein the second optical system divides the second light into a path of a reference beam and a path of a signal beam to proceed. And a micro hologram recording device sharing a signal transmission part with a transmission part. The method of claim 3, wherein
The second optical system includes a third beam splitter disposed on a path of a reference beam between the first beamsplitter and the hologram recording medium, wherein the second optical system is configured to allow the second light to travel along the path of the reference beam. And a micro hologram recording device sharing the reference beam transfer unit. 11. The method of claim 10,
And the second light source is disposed opposite the third beamsplitter. The method of claim 4, wherein
The second optical system includes a fourth beam splitter disposed between the first beam splitter and the beam expander, and a mirror that reflects the second light toward the fourth beam splitter, wherein the second optical system includes the first optical splitter. 2. A micro-hologram recording device sharing the signal beam transmitting portion so that light travels along a path of the signal beam. The method of claim 3, wherein
The signal beam transmission unit:
A beam expander extending a beam diameter of the signal beam coming from the first beam splitter;
A transmissive spatial light modulator for modulating the extended signal beam according to an image to be recorded on a hologram recording medium to load image information on the signal beam;
Fourier transform optical system for Fourier transform the signal beam carrying the image information to focus on the hologram recording medium; And
And a mirror for reflecting the signal beam from the beam expander to the transmissive spatial light modulator. The method of claim 1,
And the second light source is a laser or a light emitting diode (LED) that emits light that does not interfere with the signal beam and the reference beam. The method of claim 1,
The hologram recording medium includes a recording layer and a protective layer coated on a surface of the recording layer to protect the recording layer, wherein the second light source has a spatial interference length of the second light greater than twice the thickness of the protective layer. Micro hologram recording device configured to be small. The method of claim 1,
When the exposure energy corresponding to the lower limit of the linear recording section of the hologram recording medium is called E1, and the exposure energy corresponding to the upper limit of the linear recording section of the hologram recording medium is called E2, the second light source generates an exposure energy equal to E1. And a first light source configured to apply exposure energy of 0 to (E2-E1) to the hologram recording medium. Dividing the coherent first light into a signal beam and a reference beam;
Loading image information on the signal beam;
Providing each of the reference beam and the signal beam carrying the image information at the same position on the hologram recording medium; And
And simultaneously providing a non-interfering second light that does not interfere with the signal beam and the reference beam at the same position as the signal beam and the reference beam on the hologram recording medium. The method of claim 17,
The hologram recording medium includes a recording layer and a protective layer coated on a surface of the recording layer to protect the recording layer, wherein the spatial interference length of the second light is less than twice the thickness of the protective layer. . The method of claim 17,
The coherent first light is emitted from a first light source, and the non-coherent second light is emitted from a second light source independent of the first light source. The method of claim 19,
When the exposure energy corresponding to the lower limit of the linear recording section of the hologram recording medium is called E1, and the exposure energy corresponding to the upper limit of the linear recording section of the hologram recording medium is called E2, the second light source generates an exposure energy equal to E1. And a first light source for applying exposure energy of 0 to (E2-E1) to the hologram recording medium.

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