OPTICAL GAIN CALCULATION FOR STRAINED-QUANTUM-WELL LASERS BY THE FOURIER EXPANSION METHOD

In this paper, we extend the Fourier expansion method to calculate the optical gain of strained quantum well (QW) lasers within the 6 x 6 Lu ttinger-Kohn Hamiltonian. The optical matrix elements, in a Fourier ex pansion framework. can be derived in a simple form by averaging around the axis normal to the well plane. As a numerical example, we calcula te the band structure and the optical gain of InxGa1-xAs/InGalp/InP QW lasers. We also study the effect of the spin-orbit split-off band cou pling on the optical gain. It is shown that the calculated results are in reasonable agreement with those obtained by the conventional finit e difference method.