雪花形晶芯光子晶体光纤

设计一种新型光子晶体光纤，可在300 nm带宽范围内实现近零超平坦色散特性.光纤端面上所有空气孔按照通常的三角形规则均匀排列，中央位置十三个排列成雪花形的空气孔小于其它空气孔，这些孔共同构成光纤的纤芯.这类晶芯型光子晶体光纤与传统光子晶体光纤相比具有较大的模场面积，尤其是，通过最佳化匹配晶芯和包层中的空气孔大小可以在300 nm带宽范围内实现超平坦化色散特性，甚至可得到近零色散的平坦化色散曲线。尽管光纤的晶芯为雪花状，但近场很快会演化为类高斯型场分布.

Photonic Crystal Fiber with Snowflake Shape Crystal Core

A novel photonic crystal fiber(PCF) with near zero ultra-flattened dispersion in the range of 300 nm broadband is demonstrated.All air holes are arranged in the section according to strict triangular regulation and identical spacing.Thirteen air holes in the middle of the section arrayed in the shape of snowflake,smaller than other air holes in the outer cladding region,form the larger crystal core of PCF.Obviously,this kind of photonic crystal fiber with snowflake crystal core(SCC-PCF) has large modal field area than conventional PCF as the thirteen air holes as a whole increase the core area greatly.Furthermore,dispersion curve is very flat and near zero dispersion can be obtained in the range of 300 nm broadband by optimally matching crystal core air holes size with cladding region.Resulting from the structure of core,modal field distribution is snowflake-like,but the output of near distance field distribution will evolve into Gaussian-like shape.