Numerical Study of Multichannel Gain and Phase Recovery Dynamics of Quantum-Dot Semiconductor Optical Amplifiers by Solving Coupled Rate Equations

Abstract

We theoretically investigate the effect of multichannel pump injection on the ultrafast gain and phase recovery dynamics of quantum-dot (QD) semiconductor optical amplifiers (SOAs) by solving 10880 coupled rate equations. The ultrafast gain and phase recovery responses induced by three-channel pump injection are calculated compared with the single-channel pump injection. The gain and phase recovery response caused by three-channel pump injection is different from the summation of the three gain and phase recovery responses induced by separate single-channel pump injection. We identify the physical mechanism of the distinct gain and phase recovery responses due to different pump wavelength by considering the interplay between the Lorentzian line shape function and the spectral spacing between the pump and probe beams. The calculation results help to understand the gain and phase recovery dynamics of QD SOAs for multichannel amplification in coarse wavelength division multiplexing (CWDM) applications.