Patent attributes
In order, in the case of a holographic system, in particular for holographic data storage, comprising a radiation source for emission of a radiation an objective lens, a signal evaluation means, a detector and an optical data storage medium, the optical data storage medium having at least one data carrier layer and at least one beam-reflecting layer, to provide a solution which forms a small, compact and robust unit, in the case of which the signal beam crosses the reference beam only once, which avoids the use of optical beam splitters and requires a minimal alignment outlay, it is proposed that the objective lens has a plurality of sections, at least two beams that run parallel passing through the objective lens in a respective section and the at least two beams focusing at respectively separate locations on a plane in the optical data storage medium, at least one beam reflected in the optical data storage medium passing through the objective lens again in a respective further section.