Enhanced infrared transmission through gold nanoslit arrays via surface plasmons in continuous graphene

Tunable multi-wavelength absorption in mid-IR region based on a hybrid patterned graphene-hBN structure

In this paper, we present a patterned graphene-hBN metamaterial structure and theoretically demonstrate the tunable multi-wavelength absorption within the hybrid structure. The simulation results show that the hybrid plasmon-phonon polariton modes originate from the coupling between plasmon polaritons in graphene and phonons in hBN, which are responsible for the triple-band absorption. By varying the Fermi level of graphene patterns, the absorption peaks can be tuned dynamically and continuously, and the surface plasmon-phonon polariton modes in the proposed structure enable high absorption and wideband tunability. In addition, how different structural parameters affect the absorption spectra is discussed. This work provides us a new method for the control and enhancement of plasmon-phonon polariton interactions.

Ultra-multiband absorption enhancement of graphene in a metal-dielectric-graphene sandwich structure covering terahertz to mid-infrared regime

We investigate the absorption enhancement of an unstructured graphene sheet in a broad frequency range from terahertz (THz) to mid-infrared regime. Ultra-multiband graphene absorption enhancement is observed by integrating graphene in a metal-dielectric-graphene (MDG) sandwich structure for polarized waves. Multiple order Fabry-Perot (FP) resonances are demonstrated to be responsible for the multiband absorption. Furthermore, perfect absorption is realized by introducing the MDG structure on a metal reflector to suppress the transmission channel. In addition, the absorption peaks can be easily tuned by changing the doping level of graphene. This work may have potential for improving the performance of graphene based optoelectrical devices and can be regarded as a demonstration of a tunable broadband near-perfect metamaterial absorber.