Optical properties of Ga0.47-xIn0.53+xAs (x∼0.14) multiple-quantum-wire (MQWR) lasers prepared by the strain-induced lateral-layer ordering process were studied. A typical ratio of threshold current density, ∼10, was observed from the GaInAs MQWR lasers with contact stripes aligned to the  ( MQWR laser) and the [1¯10] ([1¯10] MQWR laser) directions. The threshold current density of the  MQWR laser is ∼30% lower than that of a Ga0.47In0.53As multiple-quantum-well (MQW) reference laser. The 77 K lasing wavelengths were 1.46, 1.57, and 1.69 μm for the MQW laser, the [1¯10] and  MQWR lasers, respectively. This strong anisotropy of threshold current densities and lasing wavelengths is the first direct evidence of the directionality of two-dimensional quantum confinement in the MQWR structure. © 1998 American Institute of Physics.