A theoretical study of a compact and highly efficient isolator consisting of nonlinear plasma and matching metamaterials

A novel, compact and highly efficient electromagnetic wave isolator is investigated theoretically, and is acquired through a wave tunneling mechanism in epsilon-negative and matching metamaterials. Nonreciprocal transmission properties are acquired via the coupling together of evanescent and propagation waves in an asymmetric configuration, constituted of nonlinear plasma alternated with matching metamaterial. Not only is a large transmission contrast achieved, but also a high forward transmission is realized. Taking four key factors into consideration, we designed a compact asymmetric multilayer structure, consisting of only five layers, to achieve the desired unidirectional wave transmissions with only 0.839 transmission contrast, 80% total transmission and 143.18 MW cm(-2) working input intensity, at an incident wave frequency of 13.8 x 10(9) s(-1), which represents better performance than was achieved with some previous designs.