Three-stimulus control ultrasensitive Dirac point modulator using an electromagnetically induced transparency-like terahertz metasurface with graphene

Abstract

This letter presents a fabricated Dirac point modulator of a graphene-based terahertz electromagnetically induced transparency (EIT)-like metasurface (GrE & MS). Dynamic modulation is realized by applying three stimulus modes of optical pump, bias voltage, and optical pump–bias voltage combination. With increasing luminous flux or bias voltage, the transmission amplitude undergoes two stages: increasing and decreasing, because the graphene Fermi level shifts between the valence band, Dirac point, and conduction band. Thus, an approximate position of the Dirac point can be evaluated by the transmission spectrum fluctuation. The maximum modulation depth is measured to be 182% under 1 V. These findings provide a method for designing ultrasensitive terahertz modulation devices.

Exploring the Application of Multi-Resonant Bands Terahertz Metamaterials in the Field of Carbohydrate Films Sensing

“…A novel plasmonic THz metamaterial composed of metal strips coupled with parallel metal strip resonators was demonstrated, which is the first emulation of the single-EIT and double-resonant bands phenomena [ 31 ]. Metamaterials with EIT windows and resonant bands characteristics have been widely observed in cut wires [ 32 ], bilayer fish-scales, and split-ring resonators (SRRs) [ 33 , 34 , 35 , 36 ]. Subsequently, the pursuit of multiple EIT windows and multi-resonant bands has also attracted considerable attention [ 37 , 38 ], as terahertz waves assisted by metamaterials with multi-resonant bands have great potential to distinguish multiple biomolecules [ 39 ].…”

All-dielectric electromagnetically induced transparency-like metasurface with breaking symmetric

“…These exhibit anomalous electromagnetic properties that cannot be found in natural materials, like negative refractive [4,5], superlens [6,7], and reversals of both the Doppler shift and Cherenkov radiation effects. On the other hand, some physics phenomenon is able to observe in metasurfaces that are difficult to realize in normal situation, for example, electromagnetically induced transparency [8,9]. In general, electromagnetically induced transparency (EIT) is created from three levels atomic system, which has destructive interference between different energy levels [10].…”