Graphene surface plasmons at the near-infrared optical regime

Abstract

Graphene has been identified as an emerging horizon for a nanoscale photonic platform because the Fermi level of intrinsic graphene can be engineered to support surface plasmons (SPs). The current solid back electrical gating and chemical doping methods cannot facilitate the demonstration of graphene SPs at the near-infrared (NIR) window because of the limited shift of the Fermi level. Here, we present the evidence for the existence of graphene SPs on a tapered graphene-silicon waveguide tip at a NIR wavelength, employing a surface carrier transfer method with molybdenum trioxides. The coupling between the graphene surface plasmons and the guiding mode in silicon waveguides allows for the observation of the concentrated field of the SPs in the tip by near-field scanning optical microscopy. Thus the hot spot from the concentrated SPs in the graphene layer can be used as a key experimental signature of graphene SPs. The NIR graphene SPs opens a new perspective for optical communications, optical sensing and imaging, and optical data storage with extreme spatial confinement, broad bandwidth and high tunability.

Towards graphene plasmon-based free-electron infrared to X-ray sources

“…Importantly, the observed plasmon lifetimes are gradually improving due to higher quality samples and fabrications of Van der Waals heterostructures [3], and are expected to increase further with advances in fabrication techniques (e.g., [30]). Similar progress is also seen for GPs of shorter free space wavelengths [31], with reports of compelling evidence [32] and recent clear signatures [33] in the near-infrared. Observations are also anticipated in the visible regime [4].…”

Second order optical nonlinearity of graphene due to electric quadrupole and magnetic dipole effects

“…All coefficients S dabc µ,T (ω 2 , ω 3 ) are odd functions of the chemical potential, and at least proportional to sgn(µ)µ 2 . Among these, S (2);xxxx µ,T (ω 2 , ω 3 ) ∝ sgn(µ)µ 4 . The form of the divergences indicates the temperature can strongly affect the values of S dabc around these divergences.…”

Graphene-plasmon polaritons: From fundamental properties to potential applications

“…As shown in Fig. 2(b), Zhang et al [57] used a guiding mode supported by a silicon waveguide to excite plasmons in graphene on top of silicon, where the graphene is doped by using the surface carrier transfer method with molybdenum trioxides. The observation of the hot spot in the tip [see Fig.…”