Low-threshold interrupted-growth step-index separate-confinement heterostructure GaAs/(Al,Ga)As lasers grown by molecular-beam epitaxy

We report preliminary results on the low‐threshold operation of interrupted‐growth GaAs/(Al,Ga)As step‐index separate‐confinement heterostructure lasers grown on misoriented substrates by molecular‐beam epitaxy. Growth was performed simultaneously on (100) substrates misoriented 1° and 6°, respectively, towards the nearest (111)A face. The 6° orientation exhibited the better morphology and lowest threshold current density (260 A cm−2 for a cavity length of 607 μm). The 1° orientation yielded the higher slope efficiency (0.43 W/A for a single facet). The growth was twice interrupted for 3 min each time for Al effusion cell temperature adjustment between the growth of the inner and outer cladding layers.