Design of a plasmonic absorber based on the nonlinear arrangement of nanodisk for surface cloak

Characterization of a plasmonic absorber for surface cloaking is proposed in this work. The improvement in the absorbance is obtained by using nanodisk particles array, and it is shown that the nonlinear structure increases the bandwidth of the absorber and reduces the reflectance by phase controlling on the surface. In this study, a corner surface with a refractive index of 3.46 is assumed as the main object which is located over a gold layer in the role of the ground for omitting the transmission and then we have implemented the nanodisks in three rows for each side of the corner with a radius of 45 nm. It is demonstrated that by utilizing this arrangement, we can obtain a reflection of −14 dB at 150 THz with a bandwidth of 8 THz for the reflecting less than −10 dB. In the following, it is illustrated that applying the nonlinear radius arrangement will increase the bandwidth to 18 THz and as a result, a bandwidth enhancement of 100% will be gained. Furthermore, the parametric studies have been used for realizing the elemental effect on improving the bandwidth. The proposed plasmonic absorber consisting of a nonlinear arrangement of nanodisks opens new prospects for surface cloaking.