一种基于非线性光纤环镜开关特性的超短光孤子产生方法

Generation of Bright and Dark Soliton Trains from Continuous-Wave Light Using the Switching Characteristics of a Nonlinear-Optical Loop Mirror

提出了一种利用非线性光纤环镜的开关特性将连续波同时转化为亮孤子和暗孤子的新方法 ,即让连续波和另一波长的调制脉冲串共同耦合入光纤环镜 ,交叉相位调制使得一部分连续波被环镜透射 ,其余部分被反射 ;再让透射波和反射波分别在反常色散光纤和正常色散光纤中传输 ,自相位调制和群速度色散之间的相互作用使得透射波和反射波分别演化为亮、暗孤子。数值计算表明 ,该方法不仅可产生脉宽比调制脉冲窄、重复频率比调制脉冲高的亮孤子和暗孤子 ,而且几乎可将全部的连续波能量转化为孤子能量。

A novel technique for the simultaneous generation of bright and dark soliton trains from continuous wave (CW) light is proposed and demonstrated numerically. It is based on the optical switching characteristics of a nonlinear optical loop mirror (NOLM) through which the CW signal is switched by a pump pulse train at another wavelength by the creation of cross phase modulation induced phase bias between the counter propagating CW components. The transmitted and reflected signals exiting from the NOLM can then evolve, respectively, into bright and dark soliton trains in fibers with the appropriate group velocity dispersion at the signal wavelength. Numerical simulations indicate that the generated solitons can be narrower than the pump pulse and that the repetition rate of the soliton trains can be higher than that of the pump pulses. Moreover, this technique permits the conversion of nearly all of the CW energy into the soliton train energy without generating pulse pedestals.