Abstract
Two-dimensional atomic heterostructures combined with metallic nanostructures allow one to realize strong light–matter interactions. Metallic nanostructures possess plasmonic resonances that can be modulated by graphene gating. In particular, spectrally narrow plasmon resonances potentially allow for very high graphene-enabled modulation depth. However, the modulation depths achieved with this approach have so far been low and the modulation wavelength range limited. Here we demonstrate a device in which a graphene/hexagonal boron nitride heterostructure is suspended over a gold nanostripe array. A gate voltage across these devices alters the location of the two-dimensional crystals, creating strong optical modulation of its reflection spectra at multiple wavelengths: in ultraviolet Fabry–Perot resonances, in visible and near-infrared diffraction-coupled plasmonic resonances and in the mid-infrared range of hexagonal boron nitride's upper Reststrahlen band. Devices can be extremely subwavelength in thickness and exhibit compact and truly broadband modulation of optical signals using heterostructures of two-dimensional materials.
Highlights
Two-dimensional atomic heterostructures combined with metallic nanostructures allow one to realize strong light–matter interactions
The gold plasmonic nanostripe array is separated from the graphene/hexagonal boron nitride (hBN) by an air gap (d)
Our modulator design could be adapted to detect the motion of a 2D heterostructure by measuring the dispersive coupling strength g 1⁄4 DE/Dz, where DE is the shift in the collective plasmon energy and Dz the displacement of the membrane
Summary
Two-dimensional atomic heterostructures combined with metallic nanostructures allow one to realize strong light–matter interactions. The advent of high-resolution nanofabrication techniques has allowed for the development of plasmonic nanostructures with a broad range of optical responses such as subwavelength confinement of light[4] and ultra-narrow diffraction-coupled resonances[5,6,7] that could lead to applications in waveguiding[8] and biosensing[9], respectively. Combining graphene with metallic nanostructures capable of supporting ultra-narrow plasmon resonances could potentially lead to the development of compact optical modulators[3]. Application of a gate voltage between graphene and the gold nanostripe sublayer leads to a reduction in the air gap height This in turn changes the effective electric field acting on graphene and hBN, modifying spectral reflection features from mid-ultraviolet to mid-infrared wavelengths. In the mid-infrared region (at a wavelength l B7 mm) the optical interrogation volume is Bl3/10, the smallest reported so far—approximately three orders of magnitude smaller than reported in ref
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
