Metamorphic lasers for 1.3-µm spectral range grown on GaAs substrates by MBE

A new method for the epitaxial formation of 1.3-µm injection lasers on GaAs substrates is reported. A metamorphic heterostructure with an In content of about 20% is deposited onto an intermediate buffer layer intended for mismatch strain relaxation. The laser active region is formed by quantum wells with a higher In content (about 40%). Lasers with 100-µm-wide stripes demonstrate room-temperature lasing at 1.29 µm with a minimum threshold current density of 3.3 kA cm2 (0.4 kA cm2 at T=85 K).