Patent ID: 7085217

Claim:
An optical information recording apparatus for recording information in a recording medium having an information recording layer for information to be recorded in through the use of holography, one side of the information recording layer being irradiated with light for recording or reproducing information, and a reflecting surface being provided on the other side of the information recording layer, the apparatus comprising: an information light generator for generating information light that carries information; a recording-specific reference light generator for generating recording-specific reference light; and a recording optical system for irradiating the information recording layer with the information light generated by the information light generator and the recording-specific reference light generated by the recording-specific reference light generator such that the information is recorded in the information recording layer in the form of an interference pattern resulting from interference between the information light and the recording-specific reference light, wherein the recording optical system projects the information light and the recording-specific reference light coaxially onto the one side of the information recording layer such that the information light and the recording-specific reference light converge to a minimum diameter at an identical position located off the reflecting surface, and thereby records the information in the information recording layer in the form of an interference pattern resulting from interference between the information light yet to impinge on the reflecting surface and the recording-specific reference light reflected by the reflecting surface and an interference pattern resulting from interference between the recording-specific reference light yet to impinge on the reflecting surface and the information light reflected by the reflecting surface.