Optomechanically induced transparency and Fano resonances in a graphene-based nanocavity

Abstract

We propose a theoretical model to obtain optomechanically induced transparency (OMIT) and Fano resonances in a nanocavity using a graphene bilayer as the intracavity medium. The motivation comes from an earlier work where Fano resonances have been reported using bilayer graphene [Nat. Nanotechnol.5, 32 (2010)NNAABX1748-338710.1038/nnano.2009.334]. We consider a similar bilayer graphene system, but inside an optomechanical nanocavity, and investigate the effects of different parameters on the output probe field. Here, one mirror of the nanocavity is considered coherently driven by the pump and probe fields, whereas the second mirror has mechanical oscillation due to the radiation pressure. We consider interaction of bilayer graphene with the optomechanical cavity and show that OMIT and Fano line shapes can be obtained corresponding to output probe field frequency. We notice that OMIT and two Fano resonances can be obtained by manipulating certain parameters, i.e., optomechanical interaction ($ {g_{mc}} $gmc), interaction of G-mode phonon and electronic state ($ {\lambda _k} $λk), and the coupling between cavity and G-mode phonon ($ {g_{cp}} $gcp). Interestingly, the system exhibits OMIT and Fano resonances simultaneously at different probe field frequencies. The accompanying dispersions are very steep, and therefore, extreme slow light can be achieved, which can lead to the realization of optical storage devices and memories. We also notice that OMIT and Fano resonances are very sensitive to the interaction of cavity modes with the oscillating mirror ($ {g_{mc}} $gmc); therefore, due to this enhanced sensitivity, our proposed system can be used to increase the sensitivity of the interferometer. Further, another advantage of using graphene is that it performs better as compared to metals in plasmonic devices.