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

Abstract

The performances of three optical devices including a refractive index sensor, a power splitter, and a 4-channel multi/demultiplexer based on graphene cylindrical resonators are proposed, analyzed, and simulated numerically by using the finite-difference time-domain method. The proposed sensor operates on the principle of the shift in resonance wavelength with a change in the refractive index of dielectric materials. The sensor sensitivity has been numerically derived. In addition, the performances of the power splitter and the multi/demultiplexer based on the variation of the resonance wavelengths of cylindrical resonator have been thoroughly investigated. The simulation results are in good agreement with the theoretical ones. Our studies demonstrate that the graphene based ultra-compact, nano-scale devices can be improved to be used as photonic integrated devices, optical switching, and logic gates.

Terahertz multi-plasmon induced reflection and transmission and sensor devices in a graphene-based coupled nanoribbons resonators

“…In particular, the sensitivity reaches an astonishingly higher value of 10 482 nm∕RIU for 1 = 100 meV. Let us mention that a similar trend is observed in [62].…”

“…To do this, the material sample inside the cavity-oscillator and its refractive index are changed; and we then investigate the resonance wavelength variations of mode (1) as a function of the sample refractive index changes. In practice, the measure of the resonance wavelength enables the determination of the unknown material, by comparing it with a look up table [62]. Quantitatively, the performance of the proposed sensor is determined by calculating its sensitivity, defined as the variation of the resonance wavelength with respect to the resonator refractive index, that is, = ∕ ( is the sample refractive index); where is given in nanometre per refractive index units nm∕RIU.…”

“…Based on this figure, we evaluate the sensitivity of the proposed sensor as = 8407 nm∕RIU. Recently, a sensitivity of 7500 nm∕RIU has been achieved in [62], whilst in [63] a value of only = 4800 nm∕RIU was reached. It is worthwhile mentioning that in these works more sophisticated graphene based resonators was studied such as circular graphene nanowires, whereas our geometry design (while being slightly more sensitive) is quite simple in comparison.…”

Graphene-Coated Nanowire Waveguides and Their Applications

“…The applications of GCNW-based tunable nanoscale devices are very important in photonics integration. Based on graphene cylindrical resonators, Asgari et al [100] proposed a refractive index sensor, a power splitter, and a four-channel multi/demultiplexer. The proposed structure was composed of two or four graphene sheets as its input/output ports and a graphene cylindrical resonator.…”