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Graphene-based hyperbolic metamaterials are well known for their optical anisotropy, high absorption of electromagnetic radiation, and low energy loss. We proposed a novel multilayer graphene-silica hyperbolic metamaterial designed as a grating structure providing narrowband near-perfect absorption of radiation in a mid-infrared band. The absorber is designed for insensitivity of the absorptance peak positioning on the angle of the incident radiation and distinct polarization selectivity of absorption for the TM mode only. A new way of handling the absorption is achieved by varying the thickness of its combined graphene-silica layers. Possibly, the type of absorber will be applicable in the fields of optical sensing, photoelectric detection, and other potential fields.

We propose a modulating plasmonic structure device which is composed of a single layer graphene above the silicon Bragg grating with the silica spacer layer. This graphene-based plasmonic modulation provides a broad stop-band with high tunability in the mid-infrared region of the transmission spectra achieved by altering the geometrical parameters of the silicon grating and the gate voltage. By engineering, a phase discontinuity into the graphene-based Bragg grating, we can selectively open a transmission window in the previous stop-band spectra. These proposed graphene-based structures are easy to fabricate and operate, which have potential applications as ultra-compact high-sensitivity sensors.

The novel plasmonic lenses based on slanted nanoslits have been proposed theoretically. The slanted nanoslits with different slant angles can provide unequal propagation distances for the surface plasmon polaritons excited by incident light. The phase retardation for wavefront shaping can be obtained to realize constructive interference on a preset single spot. We can actively modulate the position of the optical focus by adjusting the slits slant angles properly. The simulation results of the finite element method are used to verify our proposals.