Tunable, polarized and deeply modulated photoluminescence based on gold nano-islands and liquid crystal

Abstract Tunable, polarized and strongly modulated photoluminescence from liquid crystal (LC)-based Fabry Perot (FP) cavity is reported. Reflectors of this cavity are a continuous metal thin film and a plasmonic gold nano-island (NI) layer. The NI layer is selectively reflective and transparent inside and outside of the plasmonic spectral region. The NI layer strongly enhances the quality of the cavity modes in a defined plasmonic spectral area, unlike what happens in thick metal layer. The defect free nature of LC layer in the cavity can excite the FP mode and work as a light emitter by doping a dye in LC layer. Photoluminescence (PL) of the cavity is anisotropic and polarized due to the alignment of molecular dipole moment of dye along the LC director. The role of the NI layer and the LC layer on the optical quality of the cavity is investigated theoretically and experimentally. This FP cavity could be applicable in tunable optoelectronics and lasing applications.