Voltage-Controlled Optical Devices

Abstract

Achieving precise, localized reversible control of optical material properties is challenging. Fortunately, electrochemical reactions and proton pumping in a solid-state system provide reversible electrical control of the solid-state system's optical properties. Applying a voltage to a thin solid electrolyte layer, such as GdO x , splits water into O 2 and H + (with charge conservation ensured by electron transfer at the electrodes) at the interface between the solid electrolyte and an electrode. The voltage drives the protons into the solid electrolyte, changing the solid electrolyte's refractive index. Reversing the polarity of the applied voltage drives the protons out of the solid electrolyte, reversing the refractive index change. This reversible electrical control can be used to implement interference color modulation, transmission modulation, and switchable plasmonics. Because the solid electrolyte can be less than 10 nanometers thick, this electrochemical control enables highly localized control of optical properties active plasmonic devices and reconfigurable metamaterials.

1 . A device comprising:
 a first electrode;   a second electrode;   a solid electrolyte disposed between the first electrode and the second electrode; and   a voltage source, in electrical communication with the first electrode and the second electrode, to apply a voltage across the first electrode and the second electrode, the voltage splitting water into oxygen and protons at an interface between the first electrode and the solid electrolyte, the voltage generating an electric field that drives the protons toward the second electrode, the protons causing a change in an optical property of the device.