Flexibly tunable high-quality-factor induced transparency in plasmonic systems

Abstract

The quality (Q) factor and tunability of electromagnetically induced transparency (EIT)-like effect in plasmonic systems are restrained by the intrinsic loss and weak adjustability of metals, limiting the performance of the devices including optical sensor and storage. Exploring new schemes to realize the high Q-factor and tunable EIT-like effect is particularly significant in plasmonic systems. Here, we present an ultrahigh Q-factor and flexibly tunable EIT-like response in a novel plasmonic system. The results illustrate that the induced transparency distinctly appears when surface plasmon polaritons excited on the metal satisfy the wavevector matching condition with the guided mode in the high-refractive index (HRI) layer. The Q factor of the EIT-like spectrum can exceed 2000, which is remarkable compared to that of other plasmonic systems such as plasmonic metamaterials and waveguides. The position and lineshape of EIT-like spectrum are strongly dependent on the geometrical parameters. An EIT pair is generated in the splitting absorption spectra, which can be easily controlled by adjusting the incident angle of light. Especially, we achieve the dynamical tunability of EIT-like spectrum by changing the Fermi level of graphene inserted in the system. Our results will open a new avenue toward the plasmonic sensing, spectral shaping and switching.

Far‐Field Excitation of Acoustic Graphene Plasmons with a Metamaterial Absorber

“…[ 46 ] It should be noted that coupling and hybridization of multiple spatially overlapped modes is a common route to achieve multiresonant plasmonic systems. [ 47,48 ] The resonant excitation of multiple AGP cavity modes has been observed in previous experiments [ 39 ] at the same time, but the excitation strength is quite weak. The effective cavity length satisfies the F–P equation which means that it should equal an integral multiple of half the GP wavelength.…”

Tunable Surface Plasmon Polaritons with Monolithic Schottky Diodes

“…In addition, graphene has recently been investigated to integrate with SPP structures for both tunability and monolithic fabrication over a wider frequency range. [37][38][39][40] However, to the best of our knowledge, the modulation depth of such graphene based active SPP devices only reaches a few percent in experiments. 41 Here we propose to monolithically fabricate Schottky diodes with a novel subwavelength SPP structure, which enables a significant modulation of transmission, reflection, and absorption for SPPs at millimeter wave frequencies.…”

Controllable Filtering Structure Using Magnetic Coupling Between Spoof Plasmonic Waveguide and Solid Dielectric Resonators

“…Its amplitude decays exponentially in the direction vertical to the interface due to the negative permittivity of the metal, however, on the interface, it possesses the capability of transforming the traditional Sommerfeld or Zenneck surface waves into highly confined electromagnetic waves within a subwavelength region [1]. This feature provides favorable conditions to overcome the diffraction limit, and thus, SPPs have been proposed potential applications for super-resolution imaging [2], [3], electromagnetically induced transparency (EIT) [4], energy harvesting [5] and SPP power divider circuits [6]. However, natural SPPs effect can only work at optical frequency since the intrinsic electron oscillation in a metal is usually located beyond the infrared band.…”