Comments on “Theoretical Analysis of Gain-Recovery Time and Chirp in QD-SOA”

For original paper see Ben-Ezra et al., ibid., vol.17, no.9, p.1803 (2005). The authors point out that in the above letter, the rate equation model (REM) for quantum-dot (QD) semiconductor optical amplifiers (SOAs) is incorrect because the rate of carrier transition from the excited state (ES) of QD to the wetting layer (WL) was given by N_wh/tau_2w, proportional to the carrier density in the WL (N_w).