ABSTRACT
GaN-based 400-nm high-power lasers1·3l have been developed as a light source for optical disk recording. Both the Blu-ray Disk system and DVD recording system require lasers with relative intensity noise (RIN) of below -125 dB/Hz, a beam profile with low aspect ratio, and reliability of greater than 5000 h. In addition, lasers for use in optical disks capable of capacities greater than 50 GB are required to operate at an output power exceeding 100 mW in order to write information to dual-layer disks. Therefore, lower operating current, a stable beam profile, and high reliability are required to satisfy these requirements. In the present report, the authors discuss and introduce some major techniques employed to achieve these laser characteristics.
