Abstract-Angle insensitive broadband terahertz wave absorption based on molybdenum disulfide metamaterials

Xiaoyu Wang, Jicheng Wang, Zheng-Da Hu, Guilin Liu, Yan Feng,



https://www.sciencedirect.com/science/article/pii/S0749603619310341?dgcid=rss_sd_all

Two-dimensional semiconductor materials may be of importance in the field of nanophotonics. We design a broadband terahertz (THz) absorber based on molybdenum disulfide (MoS2) metamaterial, consisting of a monolayer MoS2 concentric double rings and a metal mirror separated by a thin SiO2 layer. The plasma hybridization between two MoS2 rings can effectively increase the operating bandwidth of the device under normal circumstances. The absorption rate of the structure and the absorption bandwidth can be also tuned by temperature or voltage-controlled carrier concentration. The special geometry makes our design exhibit properties that are insensitive to the angle of incidence and the polarization state of the pump source. We believe that our devices may pave the way for the design of tunable sensors in terahertz and other frequency bands.

Abstract-Hybridization-induced broadband terahertz wave absorption with graphene metasurfaces

Nanli Mou, Shulin Sun, Hongxing Dong, Shaohua Dong, Qiong He, Lei Zhou, Long Zhang,

https://www.osapublishing.org/oe/abstract.cfm?uri=oe-26-9-11728

Electromagnetic (EM) wave absorption plays a vital role in photonics. While metasurfaces are proposed to absorb EM waves efficiently, most of them exhibit limited bandwidth and fixed functionalities. Here, we propose a broadband and tunable terahertz (THz) absorber based on a graphene-based metasurface, which is constructed by a single layer of closely patterned graphene concentric double rings and a metallic mirror separated by an ultrathin SiO2 layer. Plasmonic hybridization between two graphene rings significantly enlarges the absorption bandwidth, which can be further tuned by gating the graphene. Moreover, the specific design also makes our device insensitive to the incident angle and polarization state of impinging EM waves. Our results may inspire certain wave-modulation-related applications, such as THz imaging, smart absorber, tunable sensor, etc.

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