The dynamic performance of vertical-cavity surface emitting lasers (VCSEL) diodes can be enhanced by incorporating multiquantum-well (MQW) structure in the active region. This paper addresses the transient response of MQW-VCSEL by solving the laser rate equation in the large-signal regime. The analysis makes use of the energy band structure and optical gain spectrum obtained by applying Schrödinger equation to both conduction and valance bands. Simulation results are presented for $1.3~\mu m$ InGaAs/InP VCSEL and indicate clearly that a MQW laser has higher switching speed compared with bulk laser and this finding is more pronounced with small number of wells.
The aim of this paper is to investigate the switching characteristics of hetrojunction phototransistor (HPT). First, the static characteristics of the HPT are given under ideal conditions to get a physical insight on the main parameters affecting it's response. Then the speed of response of HPT is addressed and supported by simulation results reported for $1.3~\mu m$ InGaAs/InP transistor.