Abstract: This paper briefly reviews the traveling-wave model of semiconductor optical amplifiers（SOAs）， which provides a good balance between the accuracy and the computation efficiency. This model can analyze the multichannel large-signal dynamic performance for pulse width wider than 1 ps. Obviating the constant α-factor approximation， the model can investigate the difference between gain and phase dynamics. In the frame of the theory model， an object-oriented approach is presented to the design and implementation of a dynamic SOAs simulation tool. Through abstracting common ground， the model unifies the three kinds of structures： conventional SOAs， SOAs with gain-clamping by a longitudinal laser and SOAs with gain-clamping by a vertical laser. The interface classes and interface functions are used to reduce the coupling between different modules. In order to avoid low efficiency， some private member variables that are read and modified frequently are exposed after the soft testing. Thus， the object-oriented model with high efficiency is established to analyze the dynamic device behaviors.

Key words: optoelectronics, semiconductor optical amplifiers, numerical simulation, object-oriented modeling, all-optical signal processing