Metal-Graphene Based Dynamically Tunable Bands Stop Filter

With hybrid structure, the proposed band stop filter is constructed by unit cells of simple gold strips on the stack of monolayer graphene and substrate. A stable modulation depth up to -23dB can be achieved at mid-infrared frequencies. The amount of the strips in each unit cell determines the number of the stop-bands of the filter. The location of the stop-bands not only can be adjusted by varying the length of gold strips but also can be dynamically controlled by tuning the Fermi energy level of graphene, which providing a simple and flexible approach to develop multispectral devices and can also be used as an index based sensor for its high sensitivity to the surrounding medium.