Transport-of-intensity holographic data storage based on a computer-generated hologram

To increase the recording density of computer-generated-hologram (CGH)-based holographic data storage, a phase data page reconstruction method by the transport of intensity equation (TIE) is proposed. The TIE generally requires a scanning image sensor because the phase retrieval process needs at least two defocused intensity distributions. Although the TIE is applied, the proposed method enables detection of the distributions simultaneously by utilizing an extra conjugate component reconstructed from the CGH. Experimental results show that the proposed method allows reconstructing of a phase data page without any additional elements, which keeps the optical setup simple and low cost.