Phase-change recording element for write once applications

Abstract

A WORM optical recording element includes a substrate; an amorphous phase-change recording layer disposed over the substrate; a dielectric layer disposed adjacent to the amorphous phase-change layer; a reflector layer disposed adjacent to the dielectric layer; and wherein the material and the thickness of the layers are selected such that recording can be performed on the optical recording element by using a focused laser beam to form crystalline marks in the phase-change layer using laser pulses with less than 40 nS in duration, the reflectivity of the amorphous phase as measured by a collimated beam is higher than 28% and the contrast of the read-back signal is higher than 0.6, and the second and subsequent writing over previous recording results in at least a 50% increase in read out jitter.

Dependencies are inferred from the claim text.