SPOT SHAPE ON SUPERRESOLUTION OPTICAL DISKS WITH A PHOTON-MODE MASK LAYER

The spot shape on super-resolution optical disks with a photon-mode ma sk layer was theoretically analyzed. The spot shape was found to depen d on the lifetime of the bleached state of the dyes, the light power, and the disk rotation speed. When the lifetime is short, the super-res olution spot shape is not produced at high disk speeds. On the other h and, a dye mask layer with long lifetime, such as a photochromic mask, can produce a sharp spot shape in the higher disk speed region, and t herefore is suitable for obtaining a super-resolution disk with a high data transfer rate.