Analytical and experimental study on a bent abrupt taper

This work presents an analytical coupling model for perturbed abrupt fiber tapers in single-mode fibers. In addition to LP modes, the modeling predicts the presence of LP and LP modes for a bent taper. Our model also introduces a perturbation function that can match most cases of bending variations on a taper. We have shown that the tapering and bending effect can be treated separately within one abstract formulation. Agreement amongst the model predictions and experimental results support the viability of our method.