Numerical analysis of total field propagation in linear and nonlinear single-mode tapered fibers

Total field propagation in linear and nonlinear step-index infinite-cladding tapers is investigated by use of a grid method. Spot-size and transmittance variation of the field along the taper axis is calculated for different taper angles. Interaction of the the fundamental mode with radiation field leads to spot size oscillations about the adiabatic curves, the character of the oscillations depending on the taper angle.