Continuous supersymmetric transformation for photonic design

TL;DR

This paper introduces a novel photonic mode sorter based on continuous supersymmetric transformations of dielectric profiles, achieving low cross-talk and broad wavelength operation through adiabatic index modifications.

Contribution

It presents a new SUSY-based design method for photonic mode sorters that significantly reduces cross-talk and is adaptable to different polarizations and wavelengths.

Findings

Reduces mode cross-talk by over 100 times compared to standard splitters.

Operates effectively across a broad wavelength range.

Capable of sorting both TE and TM polarized modes.

Abstract

We propose to use a continuous supersymmetric (SUSY) transformation of a dielectric permittivity profile in order to design a photonic mode sorter. The iso-spectrality of the SUSY transformation ensures that modes of the waveguide preserve their propagation constants while being spatially separated. This global matching of the propagation constants, in conjunction with the adiabatic modification of the refractive index landscape along the propagation direction results in the negligible modal cross-talk and low scattering losses in the sorter. We show that a properly optimized SUSY mode sorter outperforms a standard asymmetric Y-splitter by reducing the cross-talk by at least two orders of magnitude. Moreover, the SUSY sorter is capable of sorting either transverse-electric or transverse-magnetic polarized modes and operates in a broad range of wavelengths. The design proposed here paves the way toward efficient signal manipulation in integrated photonic devices.