Advantage of Strained Quantum Wire Lasers

It is shown theoretically that the strained quantum wire (QW) lasers have gain and differential gain much larger than those of unstrained QW lasers. Application of the strain effect to quantum wire structure leads to small hole effective mass which induces a large separation between quantized energy levels in the valence band. Thus holes concentrate efficiently into fundamental level, giving rise to increase of gain and differntial gain. The wire width at which the energy separation is comparable to the thermal energy and the relaxation broadening is 2.5 times that of the unstrained case. Broadening of energy levels due to wire width fluctuation can be reduced 1/2 times that of the unstrained case.