Nonlinear metasurfaces are multifunctional photonic elements which, unlike conventional linear metasurfaces, allow for simultaneous generation and manipulation of coherent light. This capability enables applications such as compact light sources, nonlinear beam shaping and holography, and generation of quantum correlated photon pairs.
Recently, a highly tunable metasurface device was demonstrated that combines electrical and optical switching in a broadband conversion process. The device employs electrically tunable hybrid graphene-gold plasmons to convert mid-infrared pulses into visible photons. A strong modulation of the visible light can be achieved using a broad range of mid-infrared frequencies that is 3.5X stronger than using plain graphene. Measurements indicate the device can be optically switched at Terahertz rates.
The novel work was reported by Matthew Feinstein, Alexander H. A., and Euclides Almeida from Queens College and The Graduate Center, City University of New York at The City University of New York.
The work was performed in part using an STS-Elionix ELS-G100 100 kV electron beam lithography system at the Advanced Science Research Center, GC/CUNY.
For more information see https://www.nature.com/articles/s44310-025-00071-8
Image: Schematic of metasurface nanostructure. a) Gold rods with dimensions of l = 1230 nm and w = 70 nm are arrayed on the graphene with gaps of gx = 260 nm along the long axis and gy = 150 nm along the short axis. b) SEM image of the gold rods on graphene. Scale bar is 500 nm. c) Plot of measured spectra of transmission modulation. d) Calculated charge density oscillation map. (Image use is made available under the terms of the Creative Commons BY-NC-ND 4.0 license.)