Modulation bandwidth of semiconductor lasers based on coupled quantum wells

The effect of well coupling on differential gain and maximum-modulation bandwidth for semiconductor lasers based oil coupled quantum wells is analyzed using the K factor method. We determine differential gain in coupled quantum wells within the self-consistent solution of the Poisson, Schroedinger, and 4 x 4 Luttinger-Kohn equations. The multiple-body effects of bandgap renormalization, coulombic scattering interactions, and a nonMarkovian distribution are also included. The analysis has been performed for coupled wells at 1.55 mum in an InGaAsP/InP lattice-matched system grown in the (001) direction. Our results suggest that in order to maximize modulation bandwidth and differential gain, one should design structures with barrier widths larger than 40 Angstrom. (C) 2004 Wiley Periodicals, Inc.