Ultrabroadband beam splitting in a dissipative system of three waveguides

TL;DR

This paper demonstrates that a three-waveguide system with a dissipative central waveguide can achieve ultrabroadband power splitting with minimal complexity, leveraging non-Hermitian physics without slow parameter variation.

Contribution

It introduces a novel ultrabroadband power splitting method using a dissipative waveguide system inspired by non-Hermitian quantum mechanics, avoiding the need for perfect index matching or slow evolution.

Findings

Achieves 50% power splitting over a broad bandwidth.

Does not require slow adiabatic parameter changes.

Applicable to short device lengths, especially with plasmonic waveguides.

Abstract

We show that a system of three parallel waveguides, among which the central one is dissipative, leads to an ultrabroadband power splitting associated with an overall 50% power loss. The present approach is reminiscent of non-Hermitian systems in quantum mechanics and does not require a perfect effective index matching between the external and the central waveguides. The present concept does not need any slow adiabatic evolution of the waveguide parameters and may therefore be realized over very short device lengths, especially in the case where the central waveguide is of the plasmonic type.