Abstract: An optical data storage system employing a data-modulated writing laser beam and a non-erasing reading laser beam of predetermined wavelength along with an improved optical medium comprised of multiple layers whose optical characteristics and thicknesses are chosen in conjunction with the writing and reading laser beams to provide an anti-reflection condition for unrecorded portions of the medium and a relatively high reflectivity for recorded portions of the optical medium. A preferred optical medium includes a highly reflective aluminum layer, a fluorinated hydrocarbon polymer spacer layer overlaying the reflective layer, and a gold absorber layer overlaying the spacer layer.