High-power (AlGa)As strip-buried heterostructure lasers

The characteristics of index-guided strip-buried heterostructure lasers are described. The lasers are grown by a two-step process, consisting of the initial 5-layer planar growth by MOCVD, and after etching to define the strip buried wave guide, recovery by Al0.65Ga0.35As using LPE. The devices are highly uniform, having 20 mA thresholds, quantum efficiencies of 0.65, and T0of 163°C. The TE polarized emission was in the lowest order transverse mode and consisted of ∼ 6 longitudinal modes. CW output powers of 50 mW per facet were obtained from lasers with reduced output reflectivity, and pulsed powers of 95 mW per facet from uncoated lasers have been obtained. The far-field angular widths were and in, and perpendicular to the junction plane, respectively. The total optical conversion efficiency of the coated laser emitting 50 mW CW was 41.5 percent.