Graphene-Based Fabry-Perot Resonator for Chemical Sensing Applications at Mid-Infrared Frequencies

The graphene-based Fabry-Perot resonator is presented as a chemical sensor for acting in the mid-infrared frequencies. The proposed sensor operation principle is based on chemical doping of graphene. In this process, gas molecules adsorbed on graphene surface serve as charge-carriers resulting in changing Fermi energy and conductivity of graphene. The Fabry-Perot resonator operates as an optical transducer and by making a high interaction between graphene and light transforms the conductivity changes into the spectral shift of the sensor resonance wavelength. The sensor structure is simple in order to fabricate and package. Before placing the sensor in the surroundings, graphene Fermi energy is tuned at 30 meV as a working point. Results demonstrate that the proposed sensor has a resolution 100 charge-carriers per square micrometer for spectral shifts 766 pm around resonance wavelength in the transmission spectrum. Moreover, it can be integrated with optoelectronic devices for remote sensing applications.