【摘要】 本文对于折射率分层均匀分布的多层光纤,提出了各种情况时的转移矩阵、普遍的特征方程和截频公式。将众多的JN函数归纳为一个,发展了它的变态形式,并导出了JN函数级数形式的任意项系数的递推公式。最后,对三层光纤的模式进行了研究,绘制了各种不同类型的三层光纤的特性曲线,对CVD法形成的纤芯折射率V形下陷的影响也进行了初步分析。更多还原

【Abstract】 Many optical fibers are made up of poly-regions in each of which the refractive indices are homogeneous. In this paper, applying the conception of optical networks, we present transition matrixes of this kind of optical fibers, their general characteristic equations and cut-off frequency formulae. We reduce the many original JN functions to one, expand it to modified form, and derive their characteristics. Eventually, We investigate various modes of optical fibers with only three homogeneous regions, and draw out their characteristic curves. The effect of refractive index central dip on CVD method is also appraised.更多还原