Optical multi-wavelength selectors based on distributed feedback chirped grating in arrays of graphene

We utilized the forward transmission matrix method (FTMM) to theoretically examine the transmission and reflection characteristics of distributed feedback chirped grating structures based on graphene arrays. These chirped gratings are formed by embedding single-layer graphene sheets in a bulk substrate in a non-periodic arrangement, with a consistent difference in the spatial period between adjacent graphene sheets. The entire system exhibits central symmetry. When light is incident on this chirped system, it facilitates a multi-mode resonant output. One can control the bandwidth, transmittance and cutoff wavelength of the resonances by adjusting the chemical potential of graphene, the spatial period of the chirped gratings, and the number of spatial periods. This research may provide potential applications for the development of photonic low-pass multi-wavelength selectors and filters.