Absorption and losses in one-dimensional photonic crystal perfect absorber incorporating a monolayer graphene

Abstract

We investigate the linear and nonlinear properties of a monolayer graphene embedded in a quarter-wave one-dimensional Photonic Crystal (1D-PhC) in terms of absorption and losses. In particular, we show that it is possible to achieve near-perfect narrow-band absorption when the monolayer graphene is sandwiched between two PhC mirrors with optimized pair number. The simulations reveal that the resonant wavelength and the total absorption frequency may be tuned by tilting the angle of incidence of the impinging source for both TE and TM polarizations. We also show that the losses related to the dielectric materials constituting the 1D-PhC can degrade the optical performance of the device. Preliminary fabrication tests reveal that the sputtering process does not lead to graphene structural damages affecting the material properties. Finally, by exploiting the large nonlinear response and the saturation effects of graphene monolayers we demonstrate how the structure can be dynamically change the structure from a perfect absorber to a mirror. These features make this device attractive for different applications ranging from tunable and saturable absorbers for short-pulse lasers, to graphene-based photodetectors.