Dielectric recording medium and a method of making a record.

摘要

A multi-layer information recording medium (11) for storing large amounts of information in a prescribed pattern of microscopic pits (15), formed by focusing onto the medium a beam of radiation having a prescribed wavelength and having an intensity modulated by the information to be recorded. The record medium (11) includes a substrate (29) having a light-reflective surface (31) on its upper side, a light-absorptive dielectric layer (33) overlaying the substrate and having a thickness approximately equal to an odd integral multiple of one fourth the wavelength of the beam of radiation in the dielectric material, and a thin metallic layer (35) overlaying the dielectric layer and having a light-reflective surface (37) on its lower side. During recording of the information, a substantial proportion of the intensity-modulated beam of radiation is transmitted through the metallic layer (35) to the dielectric layer (33) where it is confined, due to multiple internal reflections by the light-reflective surfaces (31,37) of the substrate and the metallic layer, until it is finally absorbed by the dielectric material. This causes an evaporation of the dielectric material (33) whenever the intensity of the beam exceeds a predetermined threshold, such evaporation carrying away the overlaying portions of the metallic layer (35) and creating the prescribed pattern of microscopic information-bearing pits (15).