Effect of well coupling on the TE optical modal gain in quantum-well based semiconductor lasers

The role of coupling between two quantum wells in TE optical modal gainis analysed within the self-consistent solution of the Poisson, Schrodinger ¨and 4 × 4 Luttinger–Kohn equations. The many-body effects of bandgaprenormalization, coulombic scattering interactions and a non-Markoviandistribution are also included. The analysis is performed for a 1.55 µmInGaAsP/InP lattice-matched system grown in the [001] direction. It showsthat electrostatics significantly changes the modal gain in both amplitude andspectrum. The gain amplitude is larger when electrostatic effects are includeddue to better charge localization in the wells. The gain spectrum also changesdue to the modification of the heterostructure potential and hence differentcoupling between the wells