半导体光放大器亚皮秒量级超快动态特性的研究

通过考虑脉冲频谱的增益色散，提出了一个分析亚皮秒光脉冲在半导体光放大器(SOA)中传输的新思路.分别对超快光脉冲在时域和频域内进行离散化，建立了一个更为合理的传输数值模型.基于该模型，观察到了脉冲频谱的明显漂移，并探讨了漂移量与脉冲载波波长、脉冲能量、脉冲宽度、SOA长度和注入电流等外部条件之间的关系，从理论上解释了文献没有证实的实验结果.同时，基于交叉增益调制原理，利用双光束结构，描述了载流子加热、光谱烧孔效应和双光子吸收等非线性效应引起的增益压缩.理论分析的结果为改善SOA的动态特性提供了指导. 关键词： 半导体光放大器 超快非线性效应 增益色散性

Theoretical study on ultrafast response of semiconductor optical amplifier

We proposed a novel method to analyze the propagation of sub-picosecond optical pulses through semiconductor optical amplifiers(SOA),fully considering spectral dispersion of ultrashort pulses. A reasonable model is established via sampling the pulses simultaneously in time domain and frequency domain. Based on the established model,we observed an evident shift of the pulse spectrum,which agrees well with the experiment results in literature. Further,the relationship is discussed respectively between the value of shift and several external conditions,including wavelength,energy,width of the pulse,length of SOA and injected current. Gain suppression induced by ultrafast nonlinearities including carrier heating,spectral hole burning and two-photon absorption is described in detail,employing two-beam configuration. The simulated results give good guidance to the improvement of ultrafast dynamic characteristics of SOAs.