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Plasmonics of two-dimensional materials have attracted increasing attention in the past few years. It provides a platform for strong light-matter interactions and enables a variety of novel applications in the infrared and terahertz ranges. In this paper, we study the plasmonic properties of a graphene-black phosphorus (G-BP) bilayer. It exhibits both strong and highly anisotropic plasmonic responses that performs beyond individual graphene and black phosphorus films. Polarization dependent, anisotropic perfect absorption can be realized in this type of two-dimensional plasmonic nanostructures with moderate doping levels. This type of hybrid architecture opens a new door for high performance two-dimensional material plasmonic devices.

Fano resonances in nanostructures have attracted widespread research interests in the past few years for their potential applications in sensing, switching and nonlinear optics. In this paper, a mid-infrared Fano resonance in a hybrid metal-graphene metamaterial is studied. The hybrid metamaterial consists of a metallic grid enclosing with graphene nanodisks. The Fano resonance arises from the coupling of graphene and metallic plasmonic resonances and it is sharper than plasmonic resonances in pure graphene nanostructures. The resonance strength can be enhanced by increasing the number of graphene layers. The proposed metamaterial can be employed as a high-performance mid-infrared plasmonic sensor with an unprecedented sensitivity of about 7.93 μm/RIU and figure of merit (FOM) of about 158.7.

Chalcogenide phase change materials enable the realization of novel, non-volatile, switchable electronic and photonic devices. In this paper, we propose a type of rewritable, non-volatile near infrared subwavelength absorber based on chalcogenide phase change materials. Our numerical simulations show that nearly perfect absorption more than 0.99 can be realized in the written state while the absorption of as-deposited or erased state is lower than 0.15 in the studied spectral range, leading to high contrast ratio of reflection more than 20 dB. Continuous tuning of the absorption spectra can be realized not only by varying the geometric parameters of the absorber but also by changing the crystallization ratio of the switched Ge 2 Sb 2 Te 5 (GST). The proposed device may find widespread applications in optical modulation, beam steering and so on.