Dynamic infrared photon detection in gate-controlled graphene gratings

A graphene metasurface, which could function as a “spectrometer-on-a-chip” for early-stage integrated optics devices, is theoretically and experimentally analyzed for detection of narrowband long-wave infrared (LWIR) emissions. Graphene films are electrically reconfigurable and lie atop a Fabry-Perot cavity, with plasmonic nanoparticles providing field enhancement. The narrowband absorption/emission of the graphene can be scanned over the long-wave infrared (LWIR) regime from 4 to 14 um by modulating the local chemical potential with a voltage. Efficient narrowband measurements of the emission spectrum of room-temperature objects can be made, or quantify adsorbed or fluorescent molecules. Such a portable and inexpensive integrated optics and optoelectronic device could electrical system health (e.g., utility system), energy infrastructure, carbon or methane management systems, or military systems. Graphene or spraycoated devices could be conformable on different, non-planar shapes. Visible color for these portable spectrometers is supplied by spraycoated biopigment Xanthommatin. Experimental results from coated samples will be reported.