Design and Fabrication of 1.35-$\mu{\rm m}$ Laser Diodes With Full Digital-Alloy InGaAlAs MQW

We report full digital-alloy In(Ga
_1-z
Al
_z
)As/InP multiple-quantum well 1.35-μm laser diodes using molecular beam epitaxy. The wells and barriers consist of five pairs of InGaAs/InAlAs (1.5 nm/0.375 nm) and four pairs of InGaAs/InAlAs (0.66 nm/0.98 nm). The separate confinement layer consists of two 60 pairs of InGaAs/InAlAs (0.66 nm/0.98 nm) and makes for an optical confinement factor of 7.07%. We obtained a continuous wave of 200 mW from a single cleaved facet of 1.6-mm long broad area LDs, with 100-μm aperture width at 10°C, and high characteristic temperature
T
₀
of 70 K. In this paper, we find that, with the MBE, the full digital-alloy technique makes bandgap engineering possible through the entire LD structure with only InGaAs/InAlAs short-period superlattices pairs.