Theoretical study on fast and slow light effects in semiconductor optical amplifiers under assist light injection

Abstract

In this paper, the fast and slow light effect of semiconductor optical amplifiers (SOAs) under assist light injection is theoretically analyzed. Coherent population oscillation (CPO) is used to induce fast and slow light effect in the theoretical model. The effects of parameters such as modulation frequency, modulation current and assist optical power on phase delay are investigated under the assist light injection. These effects are then compared with the case without assist light injection. The simulation results show that the injection of assist light can increase the phase delay of the output optical signal and enhance the slow light effect. Furthermore, when the assist light optical power is in the range of 0–15 dBm, the slow light effect is strong.