arXiv subjects

Julien Perruisseau-Carrier

Publications and source records attributed to Julien Perruisseau-Carrier.

22 records · Page 2Linked to original sources

arXiv2012

Design of Tunable Biperiodic Graphene Metasurfaces

Periodic structures with subwavelength features are instrumental in the versatile and effective control of electromagnetic waves from radio frequencies up to optics. In this paper, we theoretically evaluate the potential applications and performance of electromagnetic metasurfaces made of periodically patterned graphene. Several graphene metasurfaces are presented, thereby demonstrating that such ultrathin surfaces can be used to dynamically control the electromagnetic wave reflection, absorption, or polarization. Indeed, owing to the graphene properties, the structure performance in terms of resonance frequencies and bandwidths changes with the variation of electrostatic bias fields. To demonstrate the applicability of the concept at different frequency ranges, the examples provided range from microwave to infrared, corresponding to graphene features with length-scales of a few millimeters down to about a micrometer, respectively. The results are obtained using a full-vector semianalytical numerical technique developed to accurately model the graphene-based multilayer periodic structures under study.

cond-mat.mes-hall↗

arXiv2012

Comment on 'Encoding many channels on the same frequency through radio vorticity: first experimental test'

We show that the public experiment held in Venice by F. Tamburini et al and reported in (2012 New J. Phys. 14 033001) can be regarded as a particular implementation of Multiple-Input Multiple-Output (MIMO) communications, hence bringing no advantages with respect to known techniques. Moreover, we explain that the use of a 'vortex' mode (orbital angular momentum OAM l = 1) at one of the transmit antennas is not necessary to encode different channels since only different patterns -or similarly different pointing angles- of the transmit antennas are required. Finally, we identify why this MIMO transmission allowed decoding of two signals despite being line-of-sight. This is due to the large separation between the receiving antennas, which places the transmit antennas in the near-field Fresnel region of the receiving 'array'. This strongly limits the application of this technique in practice, since, for a fixed separation between receiving antennas, the detectable signal power from any additional vortex mode decays at least as 1/r^4.

physics.optics↗

arXiv2012

Polarimetric Control of Reflective Metasurfaces

This letter addresses the synthesis of reflective cells approaching a given desired Floquet's scattering matrix. This work is motivated by the need to obtain much finer control of reflective metasurfaces by controlling not only their co-polarized reflection but also their cross-coupling behavior. The demonstrated capability will enable more powerful design approaches -involving all field components in phase and magnitude- and consequently better performance in applications involving reflective metasurfaces. We first expose some fundamental theoretical constraints on the cell scattering parameters. Then, a successful procedure for controlling all four scattering parameters by applying parallelogram and trapezoid transformations to square patches is presented, considering both normal and oblique incidence.

physics.optics↗

arXiv2012

Graphene for Antenna Applications: Opportunities and Challenges from Microwaves to THz

The use of graphene for antennas and other electromagnetic passives could bring significant benefit such as extreme miniaturization, monolithic integration with graphene RF nanoelectronics, efficient dynamic tuning, and even transparency and mechanical flexibility. Though recently different related theoretical works have been presented, relatively few applications have been proposed and realistically assessed. In this invited talk we will briefly review the main properties of graphene and the state of the art in its theoretical and experimental characterization. Then, we will discuss a number of potential antenna applications from microwave to THz, providing in each case a critical assessment of the benefits, limitations, and remaining issues towards actual real-life implementations. Here we provide a brief overview of different devices and associated developments in our group discussed in the talk, including graphene antennas and reflectarrays at microwave and THz, plasmonic switches, isotropic and anisotropic meta-surfaces, or graphene RF-NEMS.

physics.optics↗