Abstract: This invention teaches a methodology and an optical apparatus that provides long-term, archival storage using a chemically stable, high-resolution, photosensitive emulsion, such as silver halide, for the long-term, archival storage and retrieval of data, images and text. Multiple state data substantially increasing data density is stored as vertical diffraction gratings in the archival photosensitive emulsion. The data can be read out in parallel, substantially increasing retrieval speeds beyond that of current optical and magnetic techniques.