Direct read after write optical storage medium and information storage

Abstract

An optical storage media and information storage system and method for optically recording information in optically readable form. The DRAW recording medium of the present invention consists of a three layer structure: a transparent substrate; a uniform layer of a dielectric light-responsive material having a threshold energy level at which a physical change in the material occurs; and a highly electrically conductive and highly reflective overcoating on the opposite side of the light-responsive layer from the substrate. The recording method and system allow the concentration of the writing energy to a well defined volume within the thickness of the energy responsive layer or the uniform distribution of the energy throughout the layer by setting up a standing wave within the energy responsive layer by use of the electrically conductive reflecting layer. The amount of energy absorbed by the energy responsive material from the travelling incoming wave and the standing reflected wave can be controlled by appropriately choosing the thickness of the layer and the transmissivity of the material to light of the color of the writing beam, to thereby control the depth of the areas altered by the writing beam. The invention provides a DRAW recording medium and associated DRAW recording system and method which are capable of recording information immediately readable in accordance with the International Electrotechnical Commission optical disc standard for videodiscs.