Infrared beam-steering using acoustically modulated surface plasmons over a graphene monolayer

Abstract

We model and design a graphene-based infrared beamformer based on the concept of leaky-wave (fast traveling wave) antennas. The excitation of infrared surface plasmon polaritons (SPPs) over a ‘one-atom-thick’ graphene monolayer is typically associated with intrinsically ‘slow light’. By modulating the graphene with elastic vibrations based on flexural waves, a dynamic diffraction grating can be formed on the graphene surface, converting propagating SPPs into fast surface waves, able to radiate directive infrared beams into the background medium. This scheme allows fast on–off switching of infrared emission and dynamic tuning of its radiation pattern, beam angle and frequency of operation, by simply varying the acoustic frequency that controls the effective grating period. We envision that this graphene beamformer may be integrated into reconfigurable transmitter/receiver modules, switches and detectors for THz and infrared wireless communication, sensing, imaging and actuation systems.

Modulatable optical radiators and metasurfaces based on quantum nanoantennas

“…Assume that, we would like to have a focused light sheet, the interference between fields associated with the incident plane wave (i.e., reference wave e ik·(r−r ) ) and the scattered wave (i.e., object wave e ik(r−r ) /(r − r ), which can be considered as an infinite line source) on the nanoantenna metasurface will define a hologram. For the amplitude-modulation holography, the digitized modulation pattern can be derived from the coherent superposition of optical wave fields as an intensity function [53][54][55] …”

Electrically and Magnetically Biased Graphene-Based Cylindrical Waveguides: Analysis and Applications as Reconfigurable Antennas

“…The motivation behind studying graphene-based antennas at THz in recent years [17], [21], [22], [47] can be summarized in two main points: 1) the possibility of achieving reconfiguration through graphene's field effect and 2) the high input impedance of these antennas, providing good matching to high-impedance THz sources like photomixers. These graphene antennas are essentially a planar equivalent of the dipole depicted in Fig.…”

Plasmonic metalens based on coupled resonators for focusing of surface plasmons

“…Note that the design strategy of intensity manipulation here can be achieved not only by varying d , but also any other geometric parameters that can change the coupling coefficient. For any holographic design, it is desired to have reconfigurable hologram44. Here the proposed design possesses the promising possibility for reconfigurable focusing spot, since the EIT effect could be externally controlled by integrating tunable materials as part of the unit elements354546, or directly varying the relative geometric positions using microelectromechanical system4748.…”