Graphene Sandwiches as a Platform for Broadband Molecular Spectroscopy

Abstract

Sensing is to date one of the most successful applications of surface plasmons thanks to the exceptional field amplification and sensitivity of these modes in metallic nanostructures. Here we introduce a promising detection scheme based on the propagation of strongly confined anti-bonding plasmons supported by graphene sandwiches. Instead of measuring changes in the refractive index or enhancing a restricted number of molecular absorption lines, the proposed device can recover an extended portion of the infrared spectrum of a molecule. Moreover, the extreme compression of light in graphene means that a diluted 2 nm-thick analyte can cause up to 3 dB intensity changes. The broadband capability and sensitivity also imply that one can easily identify different chemicals in a mixture and extract their respective concentration. We conclude by presenting a simple experimental set-up based on this mechanism for infrared spectroscopy which could become a cheap Fourier transform infrared accessory and an alternative to crystal-based attenuated total reflection spectroscopy.

On the Non-Local Surface Plasmons’ Contribution to the Casimir Force between Graphene Sheets

“…Graphene, the first isolated 2D material, is a honeycomb lattice of carbon atoms exhibiting exceptional physics, ranging from the room-temperature quantum Hall effect to relativistic charge carrying [17]. Its optical properties are particularly enticing thanks to its linear, Dirac cone-like dispersion (see Figure 1a); in fact, that is the driving force in several nanophotonic situations [18][19][20][21][22][23][24]. (c) Anti-symmetric (or antibonding) and symmetric (or bonding) plasmon modes between two doped graphene sheets (µ = 0.5 eV) separated by d = 50 nm athω = 0.165 eV.…”

Ab initio study of the electron energy loss function in a graphene-sapphire-graphene composite system

“…In the nanoscale devices, graphene layers typically appear in stacks [12,15] or sandwichlike structures [16] with insulating spacers between them made of polar materials, which often support strong Fuchs-Kliewer (FK), or surface optical phonon modes in the THz to mid-IR frequency range [17]. Those surface phonons strongly interact with longitudinal plasmon modes, and may therefore completely change the dispersion and damping of the Dirac plasmons in graphene [18][19][20][21], thereby seriously affecting its tunability for optoelectronic [12,17,[20][21][22] and plasmonic [23][24][25] applications in the range of frequencies of technological interest.…”

A frozen matrix hybrid optical nonlinear system enhanced by a particle lens

“…[1][2][3][4][5] To satisfy the requirements of these advanced applications, there is a growing need for optical nonlinear materials with high performance and reliability.…”