A voltage-controlled silver nanograting device for dynamic modulation of transmitted light based on the surface plasmon polariton effect

An active-controlled plasmonic device is designed and fabricated based on the index-sensitive properties of surface plasmon polaritons (SPPs). We utilize a one-dimensional silver nanograting with a period of 320 nm overlayered with a liquid crystal (LC) layer (50 μm in thickness), to transmit selectively the surface plasmon resonance (SPR) wavelength. This device realizes the active, reversible and continuous control of the transmitted light wavelength by modulating the external voltage signal applied to the LC layer. This voltage-controlled plasmonic filter has a dynamic wavelength modulation range of 17 nm, a fast respond speed of 4.24 ms and a low driving voltage of 1.06 V μm(-1). This study opens up a unique way for the design of tunable nanophotonic devices, such as a micro light sources and switches.