光子晶体光纤数值孔径测试的一种新方法

A new method for measurement of numerical aperture of photonic crystal fibers

应用光谱仪测量光子晶体光纤(PCF)的数值孔径(NA),不仅克服了传统法只能测量几个固定波长下NA的局限性,还可以对PCF与波长有关的模场面积、截止波长等参数进行研究。实验测量结果与理论计算值进行了比较,取得了满意结果。由测得的NA计算PCF的模场面积,与多极法模拟结果一致性较好。给出了NA与截止波长的关系。

Spectrometer is used to measure the numerical aperture of photonic crystal fibers.The method overcomes the limitation that the traditional measurement can only measure the numerical aperture in some fixed wavelengths,Therefore the parameters rebated with wavelength can be better studied such as：the mode field area cut-off wavelength and so on.The measured results agree well with the theoretical calculation ones.According to the measured numerical aperture,the mode field area of fiber is calculated and consistent with the results simulated by Multi-pole-method,and the both results are consistent.Finally,the relationship between cut-off wavelength and numerical aperture is given.