Long wavelength (∼1.55 &mgr;m) GaxIn1−xAs multiple‐quantum‐wire (MQWR) lasers have been grown by a single‐step molecular beam epitaxy technique. The MQWR heterostructure was fabricatedinsituusing the strain‐induced lateral‐layer ordering process. The wire formation was confirmed by cross‐sectional transmission electron microscopy and polarized photoluminescence spectroscopy. The 77 K threshold current densities for the MQWR laser diodes with laser cavities along [110] and [1¯10] directions show an anisotropy ratio of ∼10. Lasers with contact stripes aligned perpendicular to the quantum wire direction consistently show a lower threshold current density than those with stripes aligned parallel. The typical threshold current density for the MQWR laser with a stripe perpendicular to the quantum wires is ∼1 kA/cm2at 300 K. ©1995 American Institute of Physics.