利用单模光纤中调制不稳定性产生超连续激光光谱的研究

Simulation of continuous-wave supercontinuum generation using the modulation instability in single mode fibers

根据皮秒光脉冲在光纤中传输时所满足的非线性薛定谔方程,利用数值模拟方法,研究了利用准连续波作为初始输入脉冲、利用单模光纤中的调制不稳定性和光子晶体光纤的高非线性效应产生超连续激光光谱(SC)的新方法。探讨了SC的形成机理,研究了不同条件下SC的形成过程,研究结果表明:准连续波光脉冲峰值功率越高、初始脉宽越宽,越有利于SC的产生;超连续谱向长波长方向的展宽要受到光子晶体光纤长度的影响,要想获得平坦的宽带SC,必须采用合适的光子晶体光纤长度。

From the nonlinear Schrodinger equation that governs propagation of picosecond optical pulses in fibers, by using simulation method, quasi-continuous-wave supercontinuum generation by using the modula- tion instability of single mode fibers and the high nonlinearity of the photonic crystal fiber are investigated. The forming mechanism of supercontinuum generation by using quasi-continuous-wave a^s the incident source was also studied. It is shown that the higher pump power and wider pulse width generate wider supercon- tinuum. In addition, the widening at the longer wavelengths of the supercontinuum is limited by the length of the supercontinuum, that is to say, in order to obtain a smoother and broader supercontinuum, one must use an optimal fiber length.