超短孤子脉冲在色散缓变光纤中的时间抖动

Analysis on timing jitter of ultrashort solitons propagating through dispersion-decreasing fiber

通过微扰理论分析了超短孤子在色散缓变光纤(DDF)中传输的时间抖动。结果发现三阶色散和拉曼散射分别影响了孤子的位置和频率,是决定时间抖动大小的重要因素。在光纤的拉曼系数一定的情况下,选择不同的三阶色散参数,系统的时间抖动存在一个最小值。当DDF的三阶色散参数为接近零的一个负值的时候,系统时间抖动最小,这个负值与拉曼系数和传输距离有关,其绝对值随传输距离的增大而增大。在采用色散缓变光纤进行超短孤子传输的系统设计中应该重点考虑三阶色散的影响,当DDF的三阶色散参数较大的时候,必须对系统的三阶色散进行补偿,使时间抖动达到最小,能够极大地增加了孤子的传输距离。

Timing jitter of ultrashort solitons propagating in dispersion-decreasing fiber (DDF) is analyzed through perturbation theory. The result shows that the third-order dispersion (TOD) and Raman scattering affect the location and frequency of solitons respectively and dominate the timing jitter of ultrashort solitons. When Raman coefficient of DDF is constant, the timing jitter of a DDF-based system has a minimum value with different TOD parameters. When the TOD parameter of DDF has a negative value near zero, the timing jitter is minimal. This slightly negative TOD parameter is related to Raman coefficient and distance, and its absolute value increases with transmitting distance. During designing an ultrashort soliton transmitting system adopting DDF, more attentions should be paid to TOD. When the TOD of the system is large, it should be compensated to minimize the timing jitter so that to extend the transmitting distance of solitons.