Effects of physical parameters on the reflection minimum in graphene based Otto configuration

We study the electromagnetic response of Otto configuration including graphene layer in THz frequencies (.5-10 meV). Due to the excitation of SPPs a minimum in the intensity of the reflected beam appears at the angle of total internal reflection. The position of the minimum depends on the physical parameters of the structure. We study its position changing the angle and frequency of incident beam. Effects of the physical parameters such as the thickness of the air gap, dielectric constant of the substrate and conductive tunability of graphene are investigated. Our results can be important in designing the SPR based devices