Transmittance characteristics and tunable sensor performances of plasmonic graphene ribbons

Abstract

We investigate the transmittance characteristics of graphene ribbons numerically. It is found that the transmission dips originate from the transverse and longitudinal resonances of edge graphene plasmon modes, supported by the graphene ribbon resonator. The environmental refractive index changes are detected by measuring the resulting spectral shifts of the resonant transmission dip, so the graphene ribbons can be applied to plasmonic sensor in infrared. Simulation results show that sensing performances for each resonant mode are similar, and figure of merit can be up to 6. Beside, thanks to the tunable permittivity of graphene by bias voltages, the transmittance spectra and sensor performances can be easily tuned.

Tunable nano-scale graphene-based devices in mid-infrared wavelengths composed of cylindrical resonators

“…A comparison with the literature indicates that other graphene-based refractive index sensors [54][55][56], have been designed in the mid infrared wavelengths with the maximum sensitivity values of 1040, 590, and 1445 nm/RIU, respectively. In [57], a refractive index sensor based on the graphene ribbons is proposed with the sensitivity in the range of 2700-3100 nm/RIU. Also, in [58], a sensitivity up to 4525 nm/RIU has been achieved.…”

Tunable unidirectional reflectionless propagation in non-Hermitian graphene plasmonic waveguide system

“…It is found that graphene plasmonic EPs increases from 31.89 to 39.38 THz, as shown in figure 6(h). The EPs blueshift with increasing E f , the reason being that the decrease of Re(n eff ) with E f leads to the blueshift of the resonant frequencies for resonators A and B [40,41]. The forward reflection of the system is always near to 0, the backward reflection is >26%, and the reflection contrast ratios are also always >0.99 at graphene plasmonic EPs.…”

“…The fundamental edge graphene surface plasmon polaritons mode (EGSPPs) propagates along the ribbon waveguide [40,41], and we can use TCMT to analyze the dynamical propagation of EGSPPs. The time evolutions of EGSPPs' amplitudes a and b can be obtained by the following equations:…”

Filtering characteristics of a graphene ribbon with a rectangle ring in infrared region

“…4 plots the magnetic field distributions |H z | for λ = 29.24µm(a), 21.04µm(b), 17.12µm(c), 16.66µm(d), 14.42µm(e), 13.06µm(f), 12.38µm(g), 11.54µm(h), and 11µm(i), respectively. The anti-symmetrical distribution |H z | in the ring structure demonstrate the fundamental EGPs modes are excited, which are the same with Fig.…”