Hologram recording device

A hologram recording device comprising:

• a light outputting unit configured to sequentially output a plurality of laser beams having different wavelengths such that the laser beams are coaxial with one another, the light outputting unit including:
• an optical member that includes a plurality of optical elements arranged in an optical axis direction, the optical elements configured to reflect, in an optical direction, a first laser beam, of the plurality of laser beams, incident thereon in a direction crossing the optical axis direction, and the optical elements configured to allow a second laser beam, of the plurality of laser beams, incident thereon in the optical axis direction to pass therethrough, and
• a plurality of laser beam sources configured to emit the plurality of laser beams having different wavelengths, to radiate the laser beams to the optical member, and that are arranged so that third laser beam, of the plurality of laser beams, emitted from a laser beam source among the laser beam sources exposes a recording medium for a longer exposure period, than at least another of the plurality of laser beams, with the third laser beam passing through a smaller number of optical elements than the at least another of the plurality of laser beams;
• and
• a recording unit configured to sequentially irradiate the recording medium with the laser beams, which have different wavelengths, and which the light outputting unit is configured to sequentially output, so as to be coaxial with one another, for use as recording beams to record a plurality of holograms in a multiwavelength superimposing manner,
• wherein the light outputting unit includes:
• a first optical element configured to reflect, in the optical axis direction, the first laser beam incident thereon in a first direction, the first optical element is further configured to allow the second laser beam incident thereon in the optical axis direction to pass therethrough and outputting the second laser beam,
• a second optical element configured to reflect, in the optical axis direction, a fourth laser beam incident thereon in a second direction and to cause the fourth laser beam to be incident on the first optical element, the second optical element is further configured to allow a fifth laser beam incident thereon in the optical axis direction to pass therethrough and to cause the fifth laser beam to be incident on the first optical element,
• a first laser beam source configured to cause the first laser beam to be incident on the first optical element in the first direction,
• a second laser beam source configured to cause the fourth laser beam to be incident on the second optical element in the second direction, and
• a third laser beam source configured to cause the fifth laser beam to be incident on the second optical element in the optical axis direction,
• wherein, in a case in which the first laser beam, the fourth laser beam, and the fifth laser beam are emitted by respective ones of the first laser beam source, the second laser beam source and the third laser beam source, an exposure period for which the recording medium is exposed with the fifth laser beam is greater than the exposure period for which the recording medium is exposed with the fourth laser beam and the exposure period for which the recording medium is exposed with the fourth laser beam is greater than the exposure period for which the recording medium is exposed with the first laser beam, and
• wherein the first laser beam source is further configured to emit the first laser beam of a wavelength corresponding to a color blue, the second laser beam source is further configured to emit the fourth laser beam of a wavelength corresponding to a color red, and the third laser beam source is further configured to emit the fifth laser beam of a wavelength corresponding to a color green.