Adiabatic propagation algorithm for photonic lanterns

摘要

Photonic lanterns are adiabatically tapered waveguiding structures which are used for loss-less coupling of light between modes of multiple single mode fibers (SMF) to specific modes or mode groups of a few mode fiber (FMF). In this paper, we demonstrate a propagation algorithm that can be used for modelling, design and analysis of such structures. Specifically, the algorithm describes the 3D scalar beam propagation in structures with an adiabatic transition along the propagation direction. It is based on the eigenmode expansion method and exploits the property of adiabaticity. The algorithm is an invaluable tool for designing application specific photonic lanterns without running tedious finite difference beam propagation method (FDBPM) simulations. On prior reported structures, we demonstrate the applicability of our propagation algorithm, thus highlighting its advantages, efficiency and comparing it with the more common FDBPM.