双折射光子晶体光纤中基于孤子分裂的超连续光谱产生

利用亚纳焦量级、脉冲宽度为100 fs的激光脉冲在双折射光子晶体光纤中获得了450—1050 nm 的超连续光谱，且超连续光谱具有明显的分立峰状结构.分析了光谱中分立峰状结构产生的物理机制，抽运光波长处于接近零色散波长的反常色散区，形成高阶光孤子，由于高阶非线性和高阶色散的影响，高阶孤子分裂成多个基孤子，使初始光谱上演化出红移的光孤子成分和蓝移的色散波成分.理论模拟了飞秒激光脉冲在光纤中的色散特性和传输特性，较好地解释了实验结果. 关键词： 光子晶体光纤 超连续光谱产生 孤子分裂 脉冲俘获

Supercontinuum generation based on fission of higher-order solitons in bi-refringent photonic crystal fibers

The nonlinear propagation of 100 fs Ti:sapphire laser pulses in a bi-refringent photonic crystal fiber is experimentally investigated. Super-continuum generation with spectra extending from 450—1050 nm was obtained and the spectra consist of distinct peaks. The spectral broadening is shown to be caused by the mechanism of spectral broadening through fission of higher-order solitons into red-shifted fundamental solitons and blue-shifted dispersion waves. The simulation of light propagation property in the waveguide can explain well the experimental results.