GaAs/(GaAs)(4)(AlAs)(2) quantum wire lasers grown on (775)B-oriented GaAs substrates by molecular beam epitaxy

Stripe-geometry lasers with high-density GaAs/(GaAs)(4) (AlAs)(2) quantum w ires (QWRs) as an active region were grown on (7 7 5)B-oriented GaAs substr ates by molecular beam epitaxy. The (7 7 5)B QWRs were naturally formed at thick parts in a GaAs/(GaAs)(4) (AlAs)(2) quantum well with a corrugated A1 As-on-GaAs upper interface and a Aat GaAs-on-AlAs lower interface. The (7 7 5)B QWR lasers with a high one-dimensionality exhibited threshold current densities of 1.9 kA/cm(2) at 20 degrees C for a cavity length of 1 mm, whic h were about 35% lower than those of conventional QW lasers simultaneously grown on (1 0 0) GaAs substrates. Moreover, they showed a 30% higher charac teristic temperature in the range of 20-80 degrees C than the (1 0 0) QW la sers. (C) 1999 Elsevier Science B.V. All rights reserved.