Short wavelength lasers based on GaAs and GaN substrate for DVD and Blu-ray technology

Short wavelength lasers based on GaAs and GaN substrate have been developed for the application of the optical data storage. Both lasers have been required to have high performance such as the higher output power and the integration, leading to the ultra high speed recording and the lower cost. CD and DVD lasers based on GaAs are recently integrated to one chip with both high output power more than 300mW (Uchida et al., 2005). Blue lasers are also improved to show the high output power and high reliability by using GaN substrate