中文摘要：

理论推导了高斯脉冲在5种群色散剖面色散缓变光纤（DDF）中传输时的展宽因子。对比5种剖面DDF传输20km后的展宽因子发现：与常规的单模光纤（SMF）相比，任何一种DDF均能有效抑制高斯脉冲展宽；高斯型、线型和对数型DDF展宽程度基本相近，大约展宽了2．0～2．6倍；指数型DDF只展宽了约1．4倍，性能明显优于上述3种光纤；双曲线型DDF的效果最好，仅展宽了约1．05倍，基本实现无畸变稳定传输。

英文摘要：

The spreading factors are theoretically derived when a Gaussian pulse propagates in dispersion decreasing fibers（DDF） with different group dispersion profiles. The results show that every DDF can effectively restrain the pulse widening compared with the standard single-mode fiber（SMF） when a pulse propagates 20 km in the fiber. The pulse approximately widens by 2.0-2.6 times in a 20 km Gaussian or linear or logarithm DDF. The pulse approximately widens by 1.4 times in a 20 km exponential DDF whose performance is better than that of a Gaussian or linear or logarithm DDF. Especially for a hyperbolic DDF a pulse widens by 1.05 times. It is shown that a pulse can almost steadily propagate without aberration in a hyperbolic DDF.