本文建立了包括增益色散,受激喇曼散射,双光子吸收效应的理论模型,讨论了光孤子脉冲在光纤放大器中的传播.数值计算结果表明:在反常色散范围内,光孤子的放大是不稳定的.增益色散导致光脉冲对称分裂,而受激喇曼散射则导致不对称的分裂.在增益色散和受激喇曼散射的共同作用下可获得新的时域和频域特征.有限带宽的放大能抑制受激喇曼散射引起的自频移.本文对有啁啾的光孤子脉冲的放大也进行了分析.

Propagation of optical solitons in fiber amplifiers is discussed by considering a model that includes gain dispersion, intrapulse stimulated Raman scattering (ISRS) and two-photon absorption. The numerical results show that the amplification of optical solitons is unstable in the anomalous dispersion regime. The soliton pulses split into several subpulses symmetrically because of gain dispersion while ISRS results in soliton pulses split asymmetrically. An interplay between the effects of gain dispersion and ISRS can lead to novel temporal and spectral features. Bandwidth limited amplification of soliton pulses can suppress the self-frequency shift induced by ISRS. Propagation of chirped soliton pulses are also analyzed.