Abstract: A rewritable optical data storage medium (20) for high-speed recording by means of a focused radiation beam is described. The medium (20) comprises a substrate (7) carrying a stack (2) of layers, which stack (2) comprises, a substantially transparent first auxiliary layer I1 (3), a substantially transparent second auxiliary layer I2 (5) having a thickness dI2, and a recording layer (4) of a phase-change material having a thickness dp and comprising at least a composition GexSnySb1-x-y, where 0.05<x<0.30 and 0.15<y<0.30. The recording layer (4) is interposed between I1 and I2. A third auxiliary layer I3 (6) with a thickness dI3 acting as a heat sink is being present at a side of I2 opposite to the side of the recording layer. The following formula is fulfilled ?I2/dI2>5*108 W m?2 K?1, in which formula ?I2 is the heat conduction coefficient of the material of the I2 layer.

Abstract: The invention relates to a record carrier which comprises multiple sets of recording parameters for a recording process. The recording parameters define a so-called write strategy for converting an information signal to be recorded into a pulsed radiation beam for recording the information on the record carrier. By providing multiple sets of recording parameters, each set related to a specific range of recording speeds, good quality recordings are obtained at various recording speeds.

Abstract: A description is given of a multi-stack optical data storage medium (20) for rewritable recording using a focused radiation beam (30) entering through an entrance face (16) of the medium (20) during recording. The medium (20) has a substrate (1). Deposited on a side thereof is a first recording stack (2) with a phase-change type recording layer (6). The first recording stack (2) is present at a position most remote from the entrance face (16). At least one further recording stack (3), with a phase-change type recording layer (12) is present closer to the entrance face (16) than the first recording stack (2). A metal reflective layer of Cu, transparent for the radiation beam (30), is present in the further recording stack (3) and has a thickness between 2 and 10 nm. A transparent spacer layer (9) is present between the recording stacks (2, 3).

Abstract: A description is given of a rewritable optical storage medium (10) comprising a substrate (1), a first dielectric layer (2), a phase-change recording layer (3) on the basis of Ge—Sb—Te, a second dielectric layer (4), and a metal reflective layer (5). The recording layer (3) is an alloy having the composition GexSbyTez, in atom %, wherein 0<x<15, 50<y<80, 10<z<30 and x+y+z=100, and the recording layer (3) has a thickness selected from the range of 7 to 18 nm. Such a medium (10) is suitable for high data rate recording with a data rate of larger than 25 Mb/s while the recording layer (6) remains relatively thin having a relatively high optical transparency.

Abstract: A description is given of multi-stack optical data storage medium (20) for rewritable recording by means of a focused laser-light beam (30), said medium (20) having a substrate (1) with deposited on a side thereof: a first recording stick (2) comprising n phase-change type recording layer (6) at least one further recording stack (3) comprising a phase-change type recording layer (12), n transparent spacer layer (9) adjacent each further recording stack (3). The further recording stack (3) is sufficiently transmissive to ensure proper sensitivity for reading and recording in the first recording stack (2). For this purpose, at least one heat sink layer (10) made of HfNx, and 1.1=x=1.6, is present in at least one of the recording stacks (3). The heat sink layer (11) further ensures proper cooling behavior of the recording layer (12) of the further recording stack (3) in order to obtain sufficient recording performance in the further recording stack (3).