Patent ID: 6373806
Filing Date: 2002-04-16
Classification: G03H,G11B,G11C

Abstract:
A two-color hologram recording/reproducing apparatus for directing interferable signal light and reference light into a hologram recording medium to record an information signal carried by the signal light, said hologram recording medium being sensitive to a first light at a first wavelength in an ultraviolet or short-wavelength visible light band to develop light induced absorption, said apparatus comprising:means for irradiating said hologram recording medium with said first light; means for irradiating said hologram recording medium with signal light and reference light at a second wavelength longer than said first wavelength after said first light is irradiated; and gate light means for directing gate light at a third wavelength into said hologram recording medium, said gate light causing said hologram recording medium to develop a recording sensitivity to activate or inactivate a refractive index grating in accordance with existence or non-existence of a light interference pattern formed by said signal light and said reference light.