Patent ID: 7307768

Claim:
A hologram recording method comprising irradiating an optical recording medium with a signal light beam and a reference light beam which has a predetermined shape and intensity on the optical recording medium corresponding to an intensity distribution of the signal light beam on the optical recording medium, wherein: the signal light beam holds a two-dimensional digital data image and has been Fourier transformed by a lens; the intensity distribution of the reference light beam on the optical recording medium substantially coincides with the intensity distribution of the signal light beam; and the reference light beam has a wavefront which is generated by using a computer-generated hologram, the computer-generated hologram being a kinoform in which only a phase of an object light beam is recorded; and wherein: the hologram is recorded by using only a Fourier transform component of the signal light beam in which a spread ζ from a zero-order light beam of the Fourier transform image of the signal light beam is defined by the following formula: 0≦ζ≦4 fλ/d where f is a focal distance of the lens for irradiating the optical recording medium with the signal light beam, λ is a wavelength of the signal light beam, and d is a length of one side of one bit data of the signal light beam.