Adiabatic Transitions between Supersymmetric Structures as a Tool to Design Integrated Photonic Devices

Supersymmetry (SUSY), originally developed to unify the mathematical treatment of bosons and fermions, is a powerful mathematical tool with many applications in both non-relativistic quantum mechanics and Helmholtz optics [1]. The application of SUSY to optical systems has attracted a lot of attention, e.g. for mode filtering and multiplexing [2,3], exploiting the global phase-matching conditions among all the modes of two superpartner structures, except for the fundamental mode. So far, SUSY transformations have been proposed in a discrete way, i.e., evanescently coupling the superpartner structures. Here, instead, we introduce adiabatic transitions connecting superpartner profiles by smoothly modifying the transverse refractive index profile along the propagation direction, offering a new way to manipulate the modal content in systems of optical waveguides and to engineer efficient and robust photonic integrated devices [4].