Abstract: Provided is a recording material comprised of a substrate and a metallic recording layer, with the metallic recording layer comprising alternating layers of Bi and Se metal. At least five such alternating layers are used to comprise the recording layer, with from 13 to 17 layers being preferred. The resulting recording material exhibits improved sensitivity, excellent storage stability and archivability, as well as good signal-to-noise ratio.

Abstract: There is provided a method of moving the position of the focal point of an optical system in an optical data storage device. A membrane reflector having an electrically controllable surface contour is provided in the optical system and the reflector's surface contour is controlled so as to move the focal point on the data storage medium of the optical data storage device. The optical system comprises a source of plane-polarized light, a polarizing beam splitter, first and second quarter-wave plates, the membrane reflector and an objective lens.