High frequency buried heterostructure 1.5 μm GaInAsP/InP lasers, grown entirely by metalorganic vapour phase epitaxy in two epitaxial growth steps

A new high frequency buried heterostructure laser is described and fabricated using two epitaxial growth steps, grown entirely by atmospheric pressure metalorganic vapour phase epitaxy. The lasers are made with non-re-entrant mesas with the active layer narrowed to 1-2 μm by a selective etch to ensure operation in the lowest order transverse mode. The regrowth with Fe doped semi-insulating InP fills in the etched slots adjacent to the active layer and planarises the structure. The non-re-entrant mesa eliminates the anomalous rapid growth in MOVPE at the edges of the re-entrant mesas. The lasers have thresholds of 20 mA and quantum efficiencies of 46% with good linearity up to 10 mW. The laser shows a small signal microwave bandwidth of 5.8 GHz at 5 mW