阶梯色散渐变光纤及高速孤子传输

Transmission of soliton in step-decreasing-dispersion fiber

当皮秒孤子在群色散沿长度方向指数衰减的色散渐变光纤(DDF)中传输时,孤子的群色散和自相位调制保持局域平衡,宽度可以保持不变,用于孤子光通信有其特殊的优越性.但群色散分布满足要求的色散渐变光纤制造难度较大.为此,文章提出了用群色散分段均匀的光纤(称其为阶梯色散渐变光纤)来加以替代的可能性.模拟结果表明:孤子可以在由这样的光纤及滑频滤波器组成的光纤环路中稳定传输.即使群色散分布不理想的DDF,只要其各段的平均群色散满足要求,就不会严重影响孤子传输的稳定性.

Local balance between the dispersion and the selfphase modulation and the pulsewidth can be conserved when picosecond solitons propagate along a dispersiondecreasing fiber which group dispersion exponentially decreases along the fiber length at the same rate as the energy loss. However, fabricating the dispersiondecreasing fiber with perfect group dispersion distribution is not easy. A scheme of stepdispersiondecreasing fiber substituting for the dispersiondecreasing fiber has been investigated by solving numerically the generalized nonlinear Schrodinger equation in this paper. The results of the numerical simulation shows that solitons can stably propagate in the loop composed of the stepdispersiondecreasing fibers and the sliding filters.