Perfect light absorption in graphene by two unpatterned dielectric layers and potential applications

Abstract

In the spectral range from ultraviolet to near infrared, graphene lacks the capability to support plasmon polaritons, and has low optical absorptivity for applications due to its extremely small thickness. Many photonic structures based on sophisticated nanofabrication or metal plasmonics have been adopted to conquer this limitation, but they suffer from high expenses or metal parasitic losses. Here, a single-channel coherent perfect absorber simply based on two unpatterned dielectric layers is proposed to reach ~100% light absorption in monolayer and few-layer graphene. The schemes for narrowband and broadband perfect absorption in graphene are systematically demonstrated, and their potential applications on fibre-integrated narrowband perfect absorbers, high-performance optical sensors, electric-optic modulators and broadband perfect absorbers are also investigated. Our research provides a simple and costeffective method to completely trap the light from ultraviolet to near infrared in a subnanometre scale for a lot of high-performance photonic and optoelectronic devices based on graphene and potentially other 2D materials.

Graphene perfect absorber of ultra-wide bandwidth based on wavelength-insensitive phase matching in prism coupling

“…Our theoretical study has shown that almost perfect absorption (>99%) can be obtained over a wavelength range of ~300 nm with a choice of naturally available materials for the prism and the cavity layer, which is the best as far as we know. The proposed absorption scheme based on the wavelength-insensitive phase matching will be also useful for applications such as optical sensors 23–25 , solar cells 26 , thermal emitters 27 , and nonlinear optics 28 .…”

Ultra-wideband enhancement on mid-infrared fingerprint sensing for 2D materials and analytes of monolayers by a metagrating

“…In view of this, the incident wave is intended to have the electric field sufficiently located within the ultrathin layer at any incident angle. Based on our previous work, an incidence of TE wave is better to make the light-matter interaction as strong as possible [26][27][28]. Therefore, we mainly focus on the use of TE wave for the detection.…”

Enhanced Molecular Infrared Spectroscopy Employing Bilayer Graphene Acoustic Plasmon Resonator

“…Compared to plasmons in traditional noble metals, graphene is two-dimensional (2D) nanomaterials that have been demonstrated to support localized surface plasmons with considerable field confinement in the infrared region, which offer a new class of platform to realize novel electronic and photonic devices in ultracompact sizes [ 11 , 12 , 13 ]. With the advantages of low propagation loss and actively tunable resonance wavelength in the infrared region, graphene plasmons (GPs) exhibit unique features that are not available in traditional metallic surface plasmons and have been widely used in infrared spectroscopy [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. Recently, it was demonstrated that graphene plasmons can be tuned and enhanced by double or multi-layer graphene nanostructures [ 21 , 22 ].…”