High-power blue-violet laser diodes on GaN substrates

We have fabricated 400-nm-band GaN-based blue-violet laser diodes (BV-LDs) with high reliability on GaN substrates. Under 45 mW continuous wave (CW) operation at 60°C, these LDs have been operating stably for more than 1400 h. We have adopted the narrow ridge width of 1.4 μm and both sides of ridge stripe are covered with a stacked layer of Si on SiO₂. As a result, we have succeed in producing BV-LDs with a kink-free output power of more than 150 mW. The threshold current was 35.4 mA at 25°C. The operating current and voltage were 65.8 mW and 4.66 V, respectively, under 45 mW CW operation at 25°C. Their characteristics came close to surpassing the best characteristics of BV-LDs grown on ELO-GaN/sapphire, demonstrating that practical BV-LDs suitable for next-generation blu-ray disc system can be produced on GaN substrates.