Theoretical Analysis Model For Semiconductor Optical Amplifiers With Ultrafast Nonlinear Effects

Semiconductor optical amplifier (SOA) has been widely studied and applied in all optical signal processing because of many advantages, such as the high nonlinear effects inside. As the bit rate keeps increasing,the long carrier recovery time of SOAs will result in significant pattern effects and limit its applications. More and more attentions have been paid to the ultrafast nonlinear effects of SOA. By combining the basic theory with the analysis model, the ultrafast nonlinear effects of SOA are investigated in this thesis. The studies are carried out as the followings:1. The models of SOA which have been reported in literatures are introduced and analysed briefly. A relative rigorous SOA model is established. This model considers many factors including the band structures of SOA,nonuniform distribution of photon intensity and carrier density along active region, gain spectral dispersion and group velocity dispersion. Above all,the model takes into account ultrafast nonlinear effects including carrier heating(CH),spectral hole burning(SHB) and two-photon absorption when subpicosecond pulses are input.2. This model is programmed using a computer language to create an applied platform. the ideas and the method of SOA modeling are introduced in detail, and the difficulties in this model are explained, At last the methods how to extend this model are introduced.3. According to this platform,the phenomenas and the mechanism of ultrafast nonlinear effects are analyzed. The accuracy of this model is verified by comparing the simulation results with the experiment results. At last, the influences of the dispersion effects in this model are discussed.