Linear mode conversion of terahertz radiation into terahertz surface plasmon wave over a graphene-free space interface

We analyzed the linear mode conversion of incident terahertz (THz) radiation into THz surface plasmon waves (SPWs) over a surface of graphene deposited on the rippled dielectric substrate. Obliquely incident p-polarized laser light imparts oscillatory velocity to the electrons in ripple layer regime. Electron oscillatory velocity beats with ripple surface density to produce a linear current density. We examine the tunable response of mode conversion of incident terahertz radiation with respect to change in Fermi energy of graphene and incident angle. A suitable surface ripple wave number resonantly drives the THz SPW. We observe the THz SPW generation tunability with respect to Fermi energy of graphene and incident angle. The amplitude of THz SPW is increased by lowering the Fermi energy of the graphene sheet.