Spectral Analysis of a SPR Sensor based on Multilayer Graphene in the Far Infrared Range

Abstract

In this paper, we present a spectral analysis of a Surface Plasmon Resonance (SPR) sensor based on multilayer graphene (MLG) operating as a terahertz refractometer. This device's structure is based on Kretschmann configuration, and the graphene layers are modeled as surface impedances with conductivity described by the Kubo model. The structure's electromagnetic response is obtained from the Generalized Coefficients Model, considering TM excitation performed in a frequency range from 1 to 4Thz. In this approach, we evaluate the sensor response for two, three, four and five layers of graphene, equally doped. To verify the effects of MLG doping, we varied the chemical potential by 0.35eV and 0.70eV. As a result, we present the plasmonic response of the device, verifying the operating frequency range for each case of multilayer graphene. In addition, the sensitivity, FWHM and Figure of Merit (FOM) are calculated to describe the sensor performance in each demonstrated case. From the results presented, we verified that the increase in doping reduces the sensitivity of the sensor, however, it improves its FOM. The validation of the proposed model was carried out from simulations in a software based on the Finite Element Method.

Tunable Device for Long Focusing in the Sub-THz Frequency Range Based on Fresnel Mirrors

“…Recently, the enormous benefits of using electromagnetic radiation at terahertz frequencies (100 GHz to 10 THz) have been recognized. Indeed, a wide range of potential applications have been proposed in biomedicine [1], non-destructive industrial control [2], wireless communications [3], sensing [4], food quality [5], and postal security screening [6]. Because of this versatility, the handling of radiation in this frequency range is a key issue in the implementation of its practical use.…”

Long-Focusing Device for Broadband THz Applications Based on a Tunable Reflective Biprism

“…The radiation in the THz range (0.1 THz up to 10 THz) has so far demonstrated high flexibility for use in many different applications. Indeed, the implementation of tools for bio-medical [1][2][3][4][5], industrial [6,7], communications [8][9][10], and sensing [11,12] applications operating in this frequency range has received great attention, together with the prerequisite of the proper management of THz radiation, and many innovative solutions have been examined so far [13][14][15][16][17][18][19].…”