To provide a WORM optical recording element which does not have to be crystallized in advance before data in a burn-dark type based on a phase- change material is recorded on the optical recording element and which has a true WORM characteristics.
This WORM optical recording element 100 includes a substrate 121, an amorphous phase-change recording layer disposed over substrate, a dielectric layer disposed adjacent to the amorphous phase-change layer, and a reflector layer disposed adjacent to the dielectric layer. With the respect to the material and the thickness of the layers, recording can be performed on the optical recording element by using a focus 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 in the second and subsequent writing over previous recording, read out jitter is selected so as to increase by at least 50%.
CUSHMAN THOMAS RICHARD
FARRUGGIA GIUSEPPE
OLIN GEORGE RUSSELL
PRIMERANO BRUNO
VAZAN FRIDRICH
BARNARD JAMES A
