Patent ID: 8120829

Claim:
A method of holographic data recording using a data light beam having data encoded thereon and a reference light beam with the data light beam and the reference light beam directed to a recording location on a holographic recording medium containing optically active elements such that a holographic grating is formed by the interference between the data light beam and the reference light beam, wherein the reference light beam is incident on the holographic recording medium with a first angle of incidence and wherein at least a portion of the reference light beam is transmitted through the recording medium, the method comprising: reflecting the transmitted portion of the reference light beam back to the data recording location at a second angle of incidence independently controllable relative to the first angle of incidence to form a reflected light beam incident from an opposite side of the holographic recording medium to produce at least one reconstructed light beam; controlling the second angle of incidence of the reflected light beam relative to the opposite side of the holographic recording medium at the data recording location to select data for verification; and detecting the at least one reconstructed light beam during the holographic data recording to perform data verification with the reconstructed light beam.