Low-frequency active surface plasmon optics on semiconductors

Abstract

A major challenge in the development of surface plasmon optics or plasmonics is the active control of the propagation of surface plasmon polaritons (SPPs). Here, we demonstrate the feasibility of low-frequency active plasmonics using semiconductors. We show experimentally that the Bragg scattering of terahertz SPPs on a semiconductor grating can be modified by thermal excitation of free carriers. The transmission of SPPs through the grating at certain frequencies can be switched completely by changing the temperature less than 100°C. This semiconductor switch provides a basis for the development of low-frequency surface-plasmon optical devices.