Basics of a holographic data-storage system
Data are imprinted onto the object beam by shining the light through a pixelated device called a spatial light modulator. The reference beam overlaps with the object beam on the storage material, where the interference pattern is stored as a change in absorption, refractive index or thickness of the medium. A pair of lenses image the data through the storage material onto a pixelated detector array, such as a charge coupled device (CCD).