Active plasmonic devices based on ordered Au nanodisk arrays

This paper demonstrates an active plasmonic device that is based on an ordered array of Au nanodisks embedded in photoresponsive liquid crystals (LCs). The switch utilizes the photo-induced phase transition of azobenzene-doped LCs, a transition that results in different refractive indices of the LCs experienced by incident light. The localized surface plasmon resonance (LSPR) of the Au nanodisks depends on the refractive index of the disks’ surroundings. Because of this dependence, a change in refractive index of the LCs causes the LSPR to shift and thereby generates the switching effects. Discrete dipole approximation (DDA) calculations of the LSPR shifts are also presented.