Surface plasmon polaritons excitation at the interface of graphene and sodium media

The surface plasmon polaritons (SPPs) are excited at the interface of sodium and graphene media due to the effective control of dielectric functions of the two media. The absorption and dispersion behaviors of SPPs waves are modified with changing the strength of control fields and their phases. The normal and anomalous SPPs dispersion are controlled for slow and fast SPPs propagation. The group index changes in the range −2000≤ng≤2000 with the strength of control frequencies. The maximum SPPs group velocity is measured to be 1.5×105m/s and the maximum propagation length is measured to be 80λ. Furthermore, the propagation length of SPPs can be controlled with strength of the control fields and their phases variation. These controlled SPPs have potential applications in optical tweezers, nano-photonics, plasmonster technology and sensing technology