  Band structures and optical matrix elements of strained multiple
quantum-wires (QWR's) are investigated theoretically via the effective
bond-orbital model, which takes into account the effects of valence-band
anisotropy and the band mixing. In particular, the Ga$_{1-x}$In$_x$As QWR's
grown by strain-induced lateral ordering (SILO) are considered. Recently, long
wavelength Ga$_{1-x}$In$_x$As QWR lasers have been fabricated via a single step
molecular beam epitaxy technique which uses the SILO process.[1] Low threshold
current and high optical anisotropy have been achieved. Multi-axial strains
[combinations of biaxial strains in the (001) and (110) planes] for QWR's are
considered, Our calculated anisotropy in optical matrix elements (for light
polarized parallel versus perpendicular to the QWR's axis) is in good agreement
with experiment. We also find that the strain tends to increase the quantum
confinement and enhance the anisotropy of the optical transitions.
