Method of holographic recording and reproduction, holographic recording medium and holographic recording and reproducing apparatus
First Claim
1. A method of holographic recording and reproduction, the method comprising:
- recording to a holographic recording medium a wavelength variation reference pattern as a hologram at a wavelength of a recording beam, the wavelength variation reference pattern allows to determine a wavelength variation between a recording beam and a reproducing beam based on a size of an image reproduced at a wavelength of the reproducing beam;
recording to the holographic recording medium a page data pattern as a hologram at the wavelength of the recording beam, the recording beam including an information beam carrying information and a reference beam, the information beam and the reference beam being collinear and generated by spatially modulating a light beam;
detecting the wavelength variation between the recording beam and the reproducing beam based on the size of the image for wavelength variation reference obtained by reproducing the wavelength variation reference pattern at the wavelength of the reproducing beam; and
reproducing the page data pattern using the reproducing beam, the reproducing beam including a reference beam with a wavelength controlled based on the detected wavelength variation.
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Accused Products
Abstract
A method of holographic recording and reproduction includes recording to the holographic recording medium a wavelength variation reference pattern which is recorded as a hologram at a wavelength of the recording beam, recording to the holographic recording medium a page data pattern as a hologram at the wavelength of the recording beam, detecting the wavelength variation between the recording beam and the reproducing beam based on the size of an image for wavelength variation reference obtained by reproducing the wavelength variation reference pattern at a wavelength of the reproducing beam, and reproducing the page data pattern using the reproducing beam with a wavelength controlled based on the detected wavelength variation.
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Citations
17 Claims
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1. A method of holographic recording and reproduction, the method comprising:
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recording to a holographic recording medium a wavelength variation reference pattern as a hologram at a wavelength of a recording beam, the wavelength variation reference pattern allows to determine a wavelength variation between a recording beam and a reproducing beam based on a size of an image reproduced at a wavelength of the reproducing beam;
recording to the holographic recording medium a page data pattern as a hologram at the wavelength of the recording beam, the recording beam including an information beam carrying information and a reference beam, the information beam and the reference beam being collinear and generated by spatially modulating a light beam;
detecting the wavelength variation between the recording beam and the reproducing beam based on the size of the image for wavelength variation reference obtained by reproducing the wavelength variation reference pattern at the wavelength of the reproducing beam; and
reproducing the page data pattern using the reproducing beam, the reproducing beam including a reference beam with a wavelength controlled based on the detected wavelength variation. - View Dependent Claims (2, 3)
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4. A holographic recording medium, comprising:
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a substrate having a servo surface; and
a holographic recording layer formed on the substrate, the holographic recording layer comprises a first recording zone for a page data pattern and a second recording zone for a wavelength variation reference pattern. - View Dependent Claims (5, 6, 7, 8)
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9. A holographic recording and reproducing apparatus by which information is recorded as a hologram to a holographic recording medium, comprising:
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a light source;
a spatial light modulator spatially modulating intensity and/or phase of an optical beam from the light source to generate an information beam, a reference beam, and spots corresponding to a wavelength variation reference pattern;
an optical system configured to irradiate the holographic recording medium with the reference beam and the spots corresponding to the wavelength variation reference pattern as a recording beam for wavelength variation reference pattern, with the information beam and the reference beam collinearly as a recording beam, and with only the reference beam as a reproducing beam, respectively;
a photo-detector arranged on the same side as the optical system with respect to the holographic recording medium;
a wavelength variation detector detecting a wavelength variation of the reproducing beam to the recording beam based on a size of an image for wavelength variation reference obtained by the photo-detector by irradiating the wavelength variation reference pattern recorded to the holographic recording medium with the reproducing beam; and
a wavelength controller controlling wavelength of the light source based on a detection result by the wavelength variation detector. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17)
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Specification