Abstract-Ground-plane-less bidirectional terahertz absorber based on omega resonators

Alexei Balmakou, Maxim Podalov, Sergei Khakhomov, Doekele Stavenga, and Igor Semchenko
https://www.osapublishing.org/ol/abstract.cfm?uri=ol-40-9-2084

We present a new ultrathin metamaterial that acts as a frequency-selective absorber of terahertz radiation. The absorber is a square array of pairs of omega-shaped micro-resonators made of high-ohmic-loss metal. The metamaterial provides significant suppression of transmitted and reflected radiation in a bidirectional regime (that is, for both forward and backward propagating radiation). The absorber is efficient in a wide range of angles of incidence. The absence of a ground plane makes the absorber unique in comparison with numerous analogs with a ground plane that operate in a unidirectional regime. The novel metamaterial potentially enables controllable transmission of terahertz radiation in imaging systems. Analytical calculations as well as finite-element electromagnetic modeling are presented for an exemplary case with peak absorption at ∼3  THz.

© 2015 Optical Society of America

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