A theoretical study of the influence of barrier thickness variations on optical properties of a semiconductor multiple quantum well slow light device

The influence of barrier thickness variations on the operation of GaAs /AlGaAs multiple quantum well (MQW) slow light devices based on coherence population oscillations (CPOs) is explained. The variations are shown to affect the slow down factor (SDF) and bandwidth of these devices. Bloch equations and the analytical model in fractional dimension are used to analyse and simulate the slow light device. It is shown that other physical parameters of MQW structures (QW width and barrier alloy concentration) affect significantly the optical properties of the device. The presented approaches make it possible to achieve suitable values of SDF and focal energy by adjusting the barrier thickness, QW width and aluminium content. The maximum range of the centre frequency tuning is estimated to be about 1 THz in our calculations, while the slow down factor can reach a high value of 8.5 × 10⁴.