高非线性色散平坦微结构光纤的研究

利用矢量等效折射率法计算了空气孔间距和包层空气填充率对微结构光纤的非线性系数以及结构色散的影响，通过计算发现孔间距对结构色散曲线的走向起决定性作用，而包层空气填充率的影响主要是使得结构色散大小和位置发生变化，同时减小孔间距以及增大包层空气填充率都会提高非线性系数，最终设计出了几种不同特性的800nm处色散平垣高非线性微结构光纤。

Research on high nonlinearity and flattened dispersion of microstructure fibers

A vector effective index method is used to analyze the influence of the pitch and air-filling rate of cladding on the structural dispersion and nonlinear coefficient.of microstructrue filer To control the dispersion of microstructure fiber with high nonlinearity,the total dispersion is expressed the sum of structural dispersion and material dispersion.By computing and analyzing we find that pitch has decisive influence on the tendency of waveguide dispersion curve,and air filling rate generally influence the size and position of waveguide dispersion.According to the analysis results,a well-defined procedure is presented to design specific dispersion and nonlinear coefficient profiles in the Ti: Sapphire laser wavelength range.It is shown from numerical results that it is possible to design microstructure fiber with normal,anomalous,zero flattened dispersion and high nonlinear coefficient around 800nm.