<title>Electronically tunable mirror with surface plasmons</title>

Abstract

Surface plasmon tunable filter is a new technology under development at the Jet Propulsion Laboratory. This technology can also be used to build an electronically tunable mirror. When white light is incident on a metal/electro-optic material interface under certain conditions, surface plasmon waves can be excited at the interface. Photons in the wavelength range of the surface plasmon resonance will be converted into the energy of free electrons in the metal. When using nickel or a rhodium/aluminum bilayer as the metal, the bandwidth of the surface plasmon resonance can cover all of the visible spectrum. This surface plasmon resonance depends on the dielectric constants of both the metal and the electro-optic materials Therefore, application of a voltage to the electro optic material to change its dielectric constant can theoretically result in a change in the reflectivity of the interface from less than 0.5 percent to over 80 percent. The experimental results show a contrast ratio of 50:1 and a maximum reflection of 50 percent.