Abstract
Digital Optical recording is a rapidly growing technique. It needs a sensitive, long-life recording medium for the optical disks and a high power semiconductor laser installed in a read and write head. Because the sensitive layer of the disk and a focused laser beam enable widespread mass storage of digital data or documents by melting holes of about 0.7μm diam on the layer with the laser. The development of a highly sensitive and long-term stable recording medium and a high power laser diode with good optical quality are currently the subject of a great deal of interest.