Abstract: The dynamic model for a new all-optical wavelength converter (AOWC) using single-port-coupled semiconductor optical amplifier (SOA) based on cross gain modulation (XGM) is presented.Based on the dynamic model,factors which affect output extinction ratio,such as signal power,probe power,rear facet reflectivity,converted wavelength span,biased current,are analyzed respectively.The numerical result shows such a converter do have better extinction ratio character than a traditional AOWC.