Spin–orbit coupling effects on the linewidth enhancement factor of strained quantum wire lasers

The spin–orbit coupling effect on the linewidth enhancement factor (LWEF) of InGaAs/InP strained quantum wire lasers is theoretically investigated using a 6×6 Luttinger–Kohn Hamiltonian. The peak gains are overestimated for both the unstrained and the compressively strained quantum wire lasers in a 4×4 Luttinger–Kohn model. The increase in the density of states also results from the spin–orbit coupling effects. For the case of the compressively strained quantum wire lasers, the spin–orbit coupling effect greatly improves the LWEF. The unstrained system has better property of the LWEF than the compressively strained one at high injection carrier density.