Orientation dependence of the optical properties in InAs quantum-dash lasers on InP

The anisotropy of the modal gain and the linewidth enhancement factor was experimentally measured in InAs/AlGaInAs/InP semiconductor lasers with an active region composed of quantum confined structures in the form of short wires called quantum dashes. This anisotropy is due to the polarization dependence of the transition matrix element in these quantum nanostructures. The spectral dependence of the gain and linewidth enhancement factor was investigated in a wavelength range from 1540 to 1640 nm at subthreshold current densities. The largest gain and the smallest linewidth enhancement factor were obtained when the quantum dashes were oriented perpendicular to the axis of the laser cavity. (C) 2002 American Institute of Physics.