METHOD FOR TWO DIMENSIONAL CONTROL OF MARK SIZE ON AN OPTICAL DISC, WRITE STRATEGY FOR SUCH A METHOD, RECORDING MEDIUM AND RECORDER USING TWO DIMENSIONAL CONTROL OF MARK SIZE

摘要

An optical recording method is disclosed for writing a two-dimensional data pattern in a phase-change disc, i.e. a optical disc with a phase change material. The effect of thermal cross-erase is used by using the sides of the diffraction limited laser spot to heat up the adjacent track such that previously written data are partly erased. The amount of erasure is well controlled by the applied write strategy and determines the final mark size by erasing the side of the mark facing the laser spot. The mark can be initially written with a laser spot that results in a mark size that is larger than desired and subsequently, when marks in an adjacent track are being recorded, reduced in size by erasing the sides of the mark by irradiating the sides of the mark with the sides of the diffraction limited laser spot that is focused on the adjacent track.