Coherent perfect absorption and laser modes in a cylindrical structure of conjugate metamaterials

TL;DR

This paper theoretically demonstrates that conjugate metamaterials in a cylindrical structure can support both coherent perfect absorption and laser modes simultaneously, with properties dependent on size and angular momentum, advancing non-Hermitian optics.

Contribution

It introduces a novel approach to achieve CPA and laser modes in a single conjugate metamaterial cylinder, differing from parity-time symmetric systems.

Findings

CPA and laser modes can coexist in a large CM cylinder.

The phase factors for CPA and laser depend on the cylinder's size.

Excitations depend on the angular momentum of incident light.

Abstract

In this work, we theoretically find that coherent perfect absorption (CPA) and laser modes can be realized in a two-dimensional cylindrical structure composed of conjugate metamaterials (CMs). The required phase factors of CMs for achieving CPA and laser modes are determined by the geometric size of the CM cylinder, which is a unique feature compared with other non-Hermitian optical systems. Based on this property, we also demonstrate that CPA and laser modes can exist simultaneously in a CM cylinder with an extremely large size, where the excitations of CPA and laser modes depend on the angular momentum of coherent incident light. Therefore, compared with the well known parity time symmetry, our work opens up a brand-new path to obtaining CPA and laser modes, and is a significant advance in non-Hermitian optical systems.