Influence of complex conductivity on rotary penetration drag of the surface plasmon polaritons

Abstract

Recent developments in plasmonic sensors have surpassed optical sensor’s efficiency due to their ultrasmall sizes, high sensitivity, and tunability. The investigation of the rotary drag of surface plasmon polaritons has greatly enhanced the sensitivity of plasmonic sensors. In this article, Surface Plasmon Polaritons are theoretically investigated at the interface of Cesium (Cs) and Silver–silica nano-composite media. Significant enhancement in plasmon polariton’s rotary drag is observed by changing the phase and amplitude of the complex conductivity of the Cs. The maximum rotary drag achieved at the propagation length along the interface is 4 × 10 - 10 radian. The achieved value of drag at the penetration depth of silica nano-composite is of the order of 4 × 10 - 11 radian, which is ten times smaller than the drag at the propagation length. Similarly, the value of drag achieved at the penetration depth of Cs is in the order of 4 pico-radian, which is twenty times smaller than the drag at the propagation length and ten times smaller than the drag at the penetration depth of silica nano-composite. The enhancement in rotary drag of Surface Plasmon Polariton at the propagation length and penetration depths may find significant applications in sensor devices, photo-imaging, and device designing technologies.