Beam propagation in parabolically tapered graded-index waveguides

Beam propagation in parabolically tapered graded-index waveguides.

To a good approximation, the electromagnetic-propagation characteristics of graded-index waveguides can be written in terms of polynomial-Gaussian modes. For uniform quadratic-index waveguides the behavior of these modes is well known. However, there are sometimes practical reasons for using tapered waveguides, but detailed propagation solutions are known for only a few specific taper functions...

Beam propagation in periodic quadratic-index waveguides.

X-Ray Propagation in Tapered Waveguides: Simulation and Optimization

We use the parabolic wave equation to study the propagation of x-rays in tapered waveguides by numercial simulation and optimization. The goal of the study is to elucidate how beam concentration can be best achieved in x-ray optical nanostructures. Such optimized waveguides can e.g. be used to investigate single biomolecules. Here, we compare tapering geometries, which can be parametrized by li...

Light propagation in graded-index optical fibers.

An accurate numerical method is described for solving the Helmholtz equation for a general class of optical fibers. The method yields detailed information about the spatial and angular properties of the propagating beam as well as the modal propagation constants for the fiber. The method is applied to a practical graded-index fiber under the assumptions of both coherent and incoherent illuminat...

Verification of effective refraction index approach to the surface plasmon propagation in ultrathin tapered metal–dielectric–metal slot waveguides

We verify the effective refraction index approach (ERIA) developed for surface plasmon propagation in ultrathin tapered metal–dielectric–metal slot waveguides by means of comparison of exact solutions obtained within ERIA for two different profiles and different scales of tapering with finite-difference time-domain numerical simulations. We show that for smooth enough tapering, ERIA gives the p...