高斯脉冲在半导体光放大器中传输的解析表征

采用解析方法，在考虑材料损耗和色散的情况下，详细研究了无啁啾高斯脉冲和啁啾高斯脉冲在半导体光放大器中传输的物理过程，分析了强度增益、脉冲宽度和频率啁啾与线宽增强因子、色散系数、小信号增益特征参数及初始啁啾之间的关系。结果表明:当输入变换极限的高斯脉冲时，色散会引起增益压缩，脉冲展宽和频率啁啾；同样情况下，线宽增强因子越大，脉宽加宽越明显，输出脉冲啁啾越大，且随着线宽增强因子的增大，输出脉冲啁啾极大值向特征参数值较小的一边移动。当输入啁啾高斯脉冲时，初始脉冲啁啾越大，增益压缩越明显，啁啾系数为正时，脉冲单纯展宽，输出啁啾随特征参数的增大而逐渐减小，啁啾系数为负时，初始啁啾与群速度色散导致的啁啾相互竞争，致使脉冲先被压缩后被展宽；脉冲最窄处对应的特征参数随线宽增强因子的增大而先增大后减小，输出啁啾随特征参数的增大而经历振荡后趋于平稳。

Analytical characterization of Gaussian pulse propagation in semiconductor optical amplifiers with dispersion

Analytical characterization of un-chirped Gaussian pulse and chirped Gaussian pulse propagating through a semiconductor optical amplifier (SOA) is presented under consideration of material loss and dispersion. The physical mechanism of interaction between Gaussian pulse and semiconductor material is analyzed. Energy gain, pulse width as well as frequency chirp of Gaussian pulse output from SOA are investigated. The results demonstrate that linewidth enhancement factor, dispersion coefficient and feature parameter all play important roles in deciding the output pulse characteristic. The material dispersion has no obvious impact on gain compression induced by group velocity dispersion. The pulse width is broadened under the combined effect of material dispersion and group velocity dispersion. When a chirped Gaussian pulse propagates in an SOA, the same chirp component means the same gain compression no matter the chirp is positive or negative. The gain compression becomes serious with the enhancement of initial chirp. The maximum value of output pulse chirp shifts towards the smaller value of feature parameter with the increase of linewidth enhancement factor when an original un-chirped Gaussian pulse inputs. On the other hand, the output pulse chirp first increases then falls sharply, and finally reaches a steady value when a chirped Gaussian optical pulse inputs.