In-plane anisotropic lasing characteristics of (110)-oriented GaInAsP quantum-well lasers

(110)-oriented GaInAsP quantum-well (QW) lasers have been fabricated to investigate growth direction effects of the QW structure on laser performance. Large in-plane anisotropic threshold current densities in the lasers were observed between the [001] and [11̄0] cavity directions of the (110)-oriented QW structure lasers. This large anisotropy is able to be ascribed to a stronger oscillator strength for [11̄0]-polarized light. Fairly low threshold current densities of less than 0.6 kA/cm2 were obtained for the lasers with cavities along [001] direction in spite of the lower reflectivity of the reactive ion etching etched mirror surface.