Experimental Demonstration of Phase Modulation and Motion Sensing Using Graphene-Integrated Metasurfaces

摘要

Plasmonic metasurfaces are able to modify the wavefront by altering the lightintensity, phase and polarization state. Active plasmonic metasurfaces wouldallow dynamic modulation of the wavefront which give rise to interestingapplication such as beam-steering, holograms and tunable waveplates. Grapheneis an interesting material with dynamic property which can be controlled byelectrical gating at an ultra-fast speed. We use a graphene-integratedmetasurface to induce a tunable phase change to the wavefront. The metasurfacesupports a Fano resonance which produces high-quality resonances around 7.7microns. The phase change is measured using a Michleson interferometry setup.It is shown that the reflection phase can change up to 55 degrees. Inparticular the phase can change by 28 degrees while the amplitude is nearlyconstant. The anisotropic optical response of the metasurface is used tomodulate the ellipticity of the reflected wave in response to an incident fieldat 45 degree. We show a proof of concept application of our system inpotentially ultra-fast laser interferometry with sub-micron accuracy.