不同剖面色散缓变光纤中调制不稳定性分析

研究了不同群色散剖面结构的色散缓变光纤中调制不稳定性增益谱。结果表明,各种群色散剖面光纤的增益谱宽并不相同,指数型光纤的增益谱宽与传输距离是一单调关系;线型、高斯型、对数型光纤的增益谱宽变化曲线都有一个谷底;双曲线型光纤情况较为特殊,它的增益谱宽先是展宽,然后又逐渐减小。并从调制不稳定性的角度解释了用色散缓变光纤实现脉冲压缩的机理。

Modulation instability in decreasing dispersion fiber with different profiles

The gain spectrum of modulation instability is studied in the condition of decreasing dispersion fiber with different group dispersion profiles.The gain spectral width is found to vary as the type of the group dispersion profile changes.The spectral width is discovered simply relevant to transmitted distance for the type of exponential,and the curve of spectral width versus transmitted distance has a vale for the type of linear,Guassian and logarithm,but a firstly broadening and then a gradual decrease is gotten for the type of hyperbolic.Besides the mechanism of pulse compression is interpreted by means of modulation instability.