Wavelength dependence of bending loss in monomode optical fibers: effect of the fiber buffer coating

Abstract

The bend-induced optical loss in a monomode fiber has been studied as a continuous function of wavelength in the range 1.2–1.6 μm. The loss was observed to be an oscillatory function of wavelength. These observations were explained by using a model based on interference between the guided core mode in the fiber and a “whispering gallery” mode ejected from the core by the bend. The wavelengths of the minima in the oscillatory function were accurately predicted by the model when the propagation of optical power in the fiber buffer coating was taken into account.