Small-astigmatism, low-noise, and high-power self-sustained pulsation multiple-quantum-well laser diodes with a real refractive index guided self-aligned structure

Abstract

We demonstrated low-noise and high-power GaAlAs laser diodes with small astigmatism. The low-noise characteristics are realized by self-sustained pulsation due to the saturable absorption of a single-quantum-well located close to the triple-quantum-well active layer. The high-power and small-astigmatism characteristics are achieved by using a real refractive index guided self-aligned structure. The lasers showed a relative intensity noise less than −130 dB/Hz under 10% optical feedback in a very wide output-power range (5–35 mW), a stable fundamental transverse mode up to 150 mW, and astigmatism less than 1 μm.