Graphene Multilayer Photonic Metamaterials: Fundamentals and Applications

Abstract

Graphene is given high expectation due to their unique properties and advantages and has revolutionized different research fields and leads to enormous applications. However, monolayer graphene shows limited absorption due to the ultrathin thickness, which compromises the optical modulation capability. Therefore, graphene metamaterials consisting of alternatively stacked graphene and dielectric layers or graphene layer combined with conventional metamaterial structures are proposed as artificially structured materials to exploit both graphene's unique material properties and nanostructure capability of metamaterials to achieve strong optical modulations. The recent breakthrough in experimental fabrication of graphene metamaterials, in particular the solution‐based method which allows large‐area fabrication of graphene metamaterials with monolayer‐thickness controllability and nanometer surface roughness, enables extraordinary optical properties and opens various new possibilities both in research and manufacturing. In this comprehensive review, the concept of graphene metamaterials, the unique optical properties, and the enabling fabrication methods are demonstrated. The multifunctionality of graphene metamaterials offer a novel platform for manufacturing innovative optical and photonic devices with the advantages of broad working bandwidth, high efficiency, fast response, tunability, integrability, and low energy consumption. The review provides insights to future innovations for the booming graphene metamaterials and metaphotonic devices in the disciplines of optics, nanophotonics, and optoelectronics.

Harmonic Generation in Low‐Dimensional Materials

“…[66][67][68][69][70][71] More information about the linear and nonlinear optical responses of the graphene metasurfaces can be found in a recently published review. [72] HHG processes have been extensively studied for their application of generating coherent attosecond radiations in the extreme ultraviolet and soft X-ray regimes. [16] HHG methods are widely used to generate attosecond or even zepto-second pulses, which are instrumental in studying electron motion in materials.…”

“…[ 66–71 ] More information about the linear and nonlinear optical responses of the graphene metasurfaces can be found in a recently published review. [ 72 ]…”

Giant and light modifiable third-order optical nonlinearity in a free-standing h-BN film

“…Kim et al further reported thick h-BN flakes with 100 layers showing strong SHG similar to few-layer h-BN, confirming that thick h-BN flakes can serve as a nonlinear optical platform with its advantage of easy exfoliation 23 . Popkova et al first reported third-order nonlinearity of h-BN flakes with thicknesses ranging from 5 to 170 nm, determining that the h-BN third-order susceptibility χ (3) =8.4×10 -21 m 2 /V 2 , which is comparable to the cubic susceptibility of Si 3 N 4 24 . For all-optical communication systems, high optical nonlinearity is essential.…”

“…In this paper, using a unique solution-based largescale synthesize method, we developed free-standing h-BN films with high mechanical strength 25 . The third-order optical nonlinearity of such free-standing h-BN thin films was revealed and their complex nonlinear susceptibility χ (3) was characterized by using the Z-scan technique. We report, for the first time, laser modified optical nonlinearity in a free-standing h-BN film, which significantly enhances the nonlinear refraction index n 2 by more than 20 times.…”

Bi-functional Metasurface Polarizer for Reflected and Transmitted Waves

“…The polarization of electromagnetic (EM) wave is crucial in electromagnetic wave propagation, which has aroused increasing attention and interest, especially in the visible spectrum [1][2][3] . How to regulate the polarization form of EM wave in the process of propagation optionally is an essential and persistent research hotspot, which has fascinating application prospects from microwave to visible light [4][5][6][7][8] , such as spectroscopic analysis 9,10 , sensing 11,12 , and polarization imaging 13 . Conventional approaches to manipulate the polarization state of light using birefringent crystals and grating structures are subject to bulky waveplates [14][15][16] , thus the inherent defects of the conventional polarizers are large geometry and low efficiency in natural materials, which are difficult to meet in the current miniaturization of microwave and optical system integration.…”