纳米光纤的色散特性及其超连续谱产生

通过数值计算，分析了纳米光纤的色散特性，并比较了纳米光纤中不同直径和不同材料的色散特性.结果表明：二氧化硅纳米光纤有两个零色散波长，随光纤直径的增大，其色散曲线趋于平坦，零色散波长也随之发生改变；硅光纤只有一个零色散波长，且随着直径的增大，零色散波长向长波方向移动.采用广义非线性薛定谔方程来描述超短激光脉冲在纳米光纤中的传输演化过程，利用分步傅里叶方法求解方程.比较了超短脉冲在光纤不同色散区传输时，色散对超连续谱产生的影响以及脉冲波形的演化.在正常色散区，超连续谱谱宽很窄，而在零色散区和反常色散区则可产生 关键词： 色散 超连续谱产生 非线性光学 纳米光纤

Dispersion properties and supercontinuum generation in nanofiber

The dispersion properties of nanofibers was numerically simulated and caculated in details, and different dispersion properties in different diameters and materials were compared. The results show that, there are two zero dispersion wavelengths in nanofibers with silica core. With the increase of fiber diameter, the disperison curve tends to smooth and the zero dispersion wavelength also changes. When the core is silicon, it only have one zero dispersion wavelength. With the increase of diameter, its zero dispersion wavelength moves to the long-wavelength end. The generalized nonlinear Schrdinger equation is adopted to describe the evolution of ultra-short laser pulse propagating in nanofibers, and is solved by using the split-step Fourier method. The influence of dispersion on the generation of supercontinuum and the evolution of pulse profile in different dispersion regions are compared. In the normal dispersion region, the output spectral width is narrow. While in the zero dispersion region and the anomalous dispersion region, the super continuum spectrum can be obtained easily.