Theoretical analysis of gain-recovery time and chirp in QD-SOA

We present a theoretical analysis of the gain recovery and chirp characteristics of quantum-dot semiconductor optical amplifier (QD-SOA). We have derived an analytical expression for the frequency chirp in QD-SOA. The values of chirp and gain recovery time (GRT) for various signal power levels are calculated by numerical solution of the rate equations. The simulation results show that the chirp value in QD-SOA is approximately one order of magnitude lower than that in a bulk SOA. The dependences of the GRT and the chirp on the pump power level are studied.