Sakai J, Kimura T
Appl Opt. 1978 May 15;17(10):1499-506. doi: 10.1364/AO.17.001499.
A bending loss formula for optical fibers with an axially symmetric arbitrary-index profile is derived by approximating the refractive-index profile with a staircase function. The permissible bending radius R* defined for a given value of bending loss is derived. It is deduced that R* is nearly proportional to wavelength lambda when the normalized frequency nu and the refractive-index difference Delta are fixed. The ratio of R* at two different values of nu depends only on the ratio of nu. The influence of an index dip and profile smoothing on R* is numerically evaluated.
通过用阶梯函数逼近折射率分布，推导出了具有轴对称任意折射率分布的光纤的弯曲损耗公式。推导出了针对给定弯曲损耗值定义的允许弯曲半径R*。得出当归一化频率ν和折射率差Δ固定时，R几乎与波长λ成正比。R在两个不同ν值下的比值仅取决于ν的比值。数值评估了折射率凹陷和分布平滑对R*的影响。
