Small signal analysis of tin-incorporated group-IV alloys based multiple quantum well Transistor Laser

In this work we present a small signal analysis of Ge-Si 0.12 Ge 0.73 Sn 0.15 /Si 0.11 Ge 0.73 Sn 0.16 n-p-n mid-infrared transistor laser (TL) with strain-balanced Ge 0.85 Sn 0.15 multiple quantum well (QW) in the base. The frequency response of TL for common base (CB) configuration is calculated from small signal relationship between the photon density and emitter current density by solving laser rate equation and continuity equation considering the virtual states as a conversion mechanism. The result shows that modulation bandwidth initially increases then decreases with number of QW.