Optical isolation with epsilon-near-zero metamaterials

TL;DR

This paper introduces a novel method for optical isolation of circularly polarized waves using epsilon-near-zero metamaterials combined with magneto-optical materials, enabling compact and efficient isolators.

Contribution

It proposes a new principle for optical isolation using hybrid ENZ and magneto-optical metamaterials, with two practical implementation strategies.

Findings

Metamaterials with epsilon-near-zero properties can selectively transmit forward circularly polarized waves.

Hybrid structures can act as compact optical isolators for circular polarization.

Theoretical and numerical analyses confirm the effectiveness of proposed designs.

Abstract

We suggest a principle for isolation of circularly polarized waves in magnetically active extreme-parameter metamaterials. Using theoretical analysis and numerical simulations, we show that metamaterials with extreme parameters, such as epsilon-near-zero materials (ENZ), when merged with magneto-optical materials, become transparent for forward circularly polarized waves of a given handedness and opaque for backward propagating waves of the same handedness. We theoretically study two possible implementations of such hybrid materials: (1) the case of metal-dielectric stacks; and (2) rectangular waveguide near its cut-off frequency. We prove that these structures can be utilized as compact isolators for circularly polarized waves.