Perfect Impedance-Matched Isolators and Unidirectional Absorbers

TL;DR

This paper proposes a broad-band, reflectionless wave channel that supports unidirectional propagation and absorption, utilizing gyrotropic elements and gain/loss components, with potential applications in electronic and photonic circuits.

Contribution

It introduces a novel multi-functional structure capable of unidirectional wave transmission and absorption, controlled by active element interchange and gyrotropic inversion.

Findings

Supports unidirectional wave propagation with broad bandwidth

Achieves unidirectional absorption by structure inversion

Exhibits asymmetric Anderson localization with disorder

Abstract

A broad-band reflectionless channel which supports unidirectional wave propagation originating from the interplay between gyrotropic elements and symmetrically placed gain and loss constituents is proposed. Interchange of the active elements together with a gyrotropic inversion turns the same structure to a unidirectional absorber where incoming waves from a specific direction are annihilated. When disorder is introduced asymmetric Anderson localization is found. Realizations of such multi-functional architectures in the frame of electronic and photonic circuitry are discussed.