Magneto‐Optical Modulation of Photonic Spin Hall Effect of Graphene in Terahertz Region

Abstract

in the metasurfaces. [8] A giant PSHE with nearly 100% efficiency can be realized at certain metasurfaces of deep subwavelength thicknesses in gigahertz region. [9] Faraday rotation is a kind of magnetooptical (MO) effect, which means the polarization rotation of linearly polarized beam when it passes through a transparent medium. As a single layer of carbon atoms arranged in a hexagonal lattice, graphene has attracted great attention due to its gapless Dirac-type electron bandgap structure and high electron mobility. [10,11] It is a revolutionary optical material, which shows fantastic optical properties in photonics and optoelectronics for terahertz to mid-infrared applications. In terahertz region, graphene exhibits an obvious Faraday rotation, which can be used to design tunable devices based on its MO effect. [12,13] Meanwhile when a magnetic field is applied perpendicular to graphene, the hybridization of plasmons and cyclotron excitations generates graphene magneto-plasmons (GMP). The GMP modes can significantly affect the MO response of graphene waveguides. [14] Large Faraday rotation was achieved in arrays of graphene microribbons, through the excitation of the magneto-plasmons of individual ribbons. [15] In addition, the Faraday rotation can be modulated in intensity, tuned in frequency by strong magneto-plasmonic resonances in antidotpatterned graphene. [16] In this paper, we study the MO modulation of PSHE of transmitted light in graphene-substrate system in terahertz region to explore its new application in MO devices. The PSHE shift expressions in graphene-substrate system are given by the angular spectrum analysis. The MO-modulated PSHE of graphene is analyzed in detail and its potential applications in multichannel switch and barcode encryption are discussed.

Terahertz Biosensor Based on Mode Coupling between Defect Mode and Optical Tamm State with Dirac Semimetal

“…Based on this, in the following discussion, we also define the sensing layer as the defect layer. At present, the experimental measurement technology of biosensors based on micro-nano structures has been mature, and many experimental schemes can be used as references [ 30 , 31 , 32 ]. Therefore, there is no technical obstacle in the experimental verification of the above simple multilayer structures.…”

Spin Hall Effect of Light: From Fundamentals To Recent Advancements

“…[104] Graphene has also been applied to modulate the SHEL of transmitted light in the terahertz region using the magneto-optical effect. [105] When a magnetic field is applied to graphene, the spin Hall shift can be significantly modulated due to the influences of the relaxation time and Fermi energy of graphene. Experimental demonstrations of the dynamically tunable spin Hall shift under magnetic [106] and electric [107] fields have been reported.…”

Terahertz chiral sensing and magneto-optical enhancement for ferromagnetic nanofluids in the chiral metasurface

“…For further development of the THz application system, there is a high demand for efficient devices for sensing and manipulating THz waves in their amplitude, phase, and polarization [5][6][7][8] . The unique magnetic anisotropy, nonreciprocity, and magnetic tunability of magneto-optical material make them play an irreplaceable role in the isolator, magneto-optical polarization convertor, modulator, and magnetic field sensor [9][10][11][12][13][14] . However, researches on the magnetic properties of THz waves lag seriously, so it is necessary to fill the "terahertz gap" by not only electrical but also magnetic means.…”