光孤子在色散缓变光纤中传输时的等价增益

从准非线性Ｓｃｈｒ?ｄｉｎｇｅｒ（ＮＬＳ）方程出发，导出了色散缓变光纤中光孤子脉冲传输所满足的与常规光纤中含增益效应等价的ＮＬＳ方程，给出了该方程的微扰解析解和光孤子脉冲宽度演化表达式。对于阶跃型单模光纤，得到了光纤几何参数与增益系数之间的一般函数关系。最后采用数值模拟方法模拟了不同色散缓变光纤中光孤子脉冲传输特性，指出色散缓变光纤不仅能补偿光纤损耗对孤子脉冲的展宽效应，而且能压缩光孤子脉冲，因而预计它可能有较广泛的应用前景。 关键词：

EQUIVALENT GAIN EFFECT OF SOLITON PULSES IN THE FIBERS WITH SLOWLY DECREASING DISPERSION

The nonlinear Schr?dinger equation (NLS) including gain effect is derived from quasi-NLS equation which describes the behavior of soliton pulses in the fiber with slowly decreasing dispersion. The solution of this equation and pulse-width evolution expression are given. For step-index profile single-mode fiber, ordinary relationship between fiber structure parameters and gain coefficient are obtained. Numerical simulation shows that the fiber with slowly decreasing dispersion not only can compensate for soliton broadening caused by fiber loss, but also can compress soliton pulses.
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