Broadband stop filters for THz waves using H-shaped metamaterials with dual electronic-plasmonic functionality

Terahertz (THz) waves have attracted extensive attention recently owing to their spectral specificity and transmission properties. For developing THz technologies, filters are significant devices because they can manipulate waves transmission. Metamaterials (MMs) possess unique optical characteristics that are not available in natural materials, have been developed for THz filters. However, reported MMs with separated units only excite plasmonic resonances, which limits their application. Here, broadband stop filters based on H-shaped MMs (H-MMs) for THz waves were proposed. The H-MM has two continuous metallic arms that can flow the electric current, allowing it to benefit electronic applications meanwhile keeping the plasmonic characteristics. A stopband with a central frequency of 0.65 THz and a -10 dB bandwidth of 458 GHz was experimentally demonstrated. Moreover, this filter can freely tune its bandwidth and central frequency by designing its geometry, which provides it with potential in wide THz applications such as THz communications.