Stable high-power operation of self-aligned stepped substrate (S3) AlGaInP visible laser diode with small beam aspect ratio

The authors have developed a selfaligned stepped substrate (S3) AlGaInP laser diode with a small beam aspect ratio and stable high-temperature high-output-power operation. The laser had the index-guided laser structure, and was fabricated by only one-step MOVPE. The width of the laser waveguide was decreased to enlarge the beam divergence in the horizontal direction. Also, the strained multiquantum-well active layer was modified to reduce the high temperature operation current by introducing GaInAsP well layers. As a result, the laser had a beam aspect ratio of 1.5 and stable 35 mW operation for more than 1000 h at 50°C.