In this work, we analyze the near-field radiative heat transfer (NFRHT) between finite-thickness planar fused silica slabs coated with graphene gratings. We go beyond the effective medium approximation by using an exact Fourier modal method equipped with specific local basis functions, and this is needed for realistic experimental analysis. In general, coating a substrate with a full graphene sheet has been shown to decrease the NFRHT at short separations (typically for d < 100 nm) compared to the bare substrates, where the effective medium approximation consistently overestimates the radiative heat flux, with relative errors exceeding 50%. We show that by patterning the graphene sheet into a grating, the topology of the plasmonic graphene mode changes from circular to hyperbolic, allowing to open more channels for the energy transfer between the substrates. We show that at short separations, the NFRHT between slabs coated with graphene gratings is higher than that between full-graphene-sheet coated slabs and also than that between uncoated ones. We also exhibit a significant dependence of the radiative heat transfer on the chemical potential, which can be applied to modulate in situ the scattering properties of the graphene grating without any geometric alterations. Additionally, we compare the exact calculation with an approximate additive one and confirm that this approximation performs quite well for low chemical potentials. This work has the potential to unveil new avenues for harnessing non-additive heat transfer effects in graphene-based nanodevices.

We present an accurate and simple semi analytical model for studying the magneto- plasmonic response of a 1D subwavelength graphene strip grating under an external static mag- netic field. In this model, the graphene sheet is considered as an anisotropic layer with atomic thickness. Under these conditions and in contrast to the previous works, an effective medium approach (EMA) is applied to the graphene permittivity tensor and a rigorous phase correction is required to take into account the periodicity effect. The resonance phenomena occurring into the structure are taken into account in the model using the scattering matrix approach. The re- flection and transmission spectra of the structure are then given as the sum of two contributions, the scattering contribution and the single strip contribution. In order to numerically validate and evaluate the proposed model, the results have been compared with those obtained from the PMM [1, 2] method and from methods published in the literature [3, 4]. This simple approach is useful to better understand graphene surface magnetoplasmons GSMPs and may facilitate the design of various tunable devices based on graphene magnetoplasmonics.

In this work, we propose a novel hybrid magneto plasmonic structure based on graphene and doped InSbto enhance the magneto optical Kerr effect at terahertz frequencies.The structure is composed of a 1D periodic dopedInSb inlayed between a metallic backgate and a dielectric/doped graphene sheet .By computing the optical responseof this structure, w e show an enhanced and large Kerr rotation in a wide range of THz frequencies compared to thatinduced by a single graphene sheet and/or a doped magnetized InSb

Design of the metallic contact grid at the front side of thermophotovoltaic cells is critical. Our study, based on a rigorous approach, investigates the real influence of the front metal contact grid. By modelling this grid by a metallic grating, we show that it can significantly affect the electrical power generated by the cell. Quantitative and qualitative analyses indicate behaviors which are quite different from those predicted by previous simplistic approaches.

We present a numerical approach for the solution of EM scattering from a dielectric cylinder partially covered with graphene. It is based on a classical Fourier-Bessel expansion of the fields inside and outside the cylinder to which we apply the ad-hoc boundary conditions in the presence of graphene. Due to the singular nature of the electric field at the ends of the graphene sheet, we introduce auxiliary boundary conditions to better take this reality into account.

We present a simplification of the Fourier Modal Method (FMM) for crossed gratings with subwavelength heights. We show that in this case it is possible to compute the scattering matrix of the structure without solving the eigenvalue problem which is the most expensive computational part of the FMM algorithm. This approach is very efficient and thus suitable for periodic metasurfaces.

The Fourier Modal Method [1] (FMM) is very popular and efficient approach for modelling diffraction from gratings. It can be applied to graphene gratings either by using the Zero Thickness Model (ZTM) i.e. using directly the optical conductivity of graphene in the boundary conditions, or by using the Finite Thickness Model (FTM) where graphene is seen as a slab of atomic thickness and a relative dielectric permittivity deduced from its optical conduc- tivity. For 1D gratings, the FMM based on the ZTM proves to be very efficient for the transverse electric polarization case (electric filed parallel to the direction of invariance of the strips) but suffers from low convergence in the transverse magnetic polarization case (magnetic filed parallel to the direction of invariance of the strips). This is due to a an inappropriate use of the Fourier factorization rules [1]. The FMM based on the FTM, on the other hand, doesn’t experience such a limitation but at the expense of solving an eigenvalue problem inside the grating which has been given a finite thickness. This is very demanding from the computational point of view because solving an eigenvalue problem has a cost scaling with the third power of the dimension of the matrices in play. This increases the computational cost of the approach especially for crossed gratings. Furthermore, a in a recent work [2], the authors have shown the it is possible to avoid solving this eigenvalue problem if the grating has a deep subwavelength thickness. This condition is exactly fulfilled by graphene under the FTM where it is assumed to have an atomic thickness. I will show that using such a simplification lowers the computational cost of the FMM-FTM while giving reliable and accurate results.