Holographic storage of binary coded information - uses intensity modulation of object wave compensating fluctuation of mean radiation intensity

摘要

The intensity of the object wave in the holographic storage device is modulated by the information to be stored. The volume of information to be stored in a hologram is predetermined by the number of vaster positions of a point vaster and is evaluated with regard to the number of binary ones or binary zeros assigned to the number of vaster positions. In dependence on the evaluation with the aid of suitable control means (AM') either the intensity of the reference wave (BW) during the recording of a specific value or the size of an additional exposure time is determined only for the reference wave.