| Abstract: | A tunable extraordinary optical transmission (EOT) device wherein the
tunability derives from controlled variation of the dielectric constant
of a semiconducting material (semiconductor) in evanescent-field contact
with a metallic array of sub-wavelength apertures. The surface plasmon
resonance wavelength can be changed by changing the dielectric constant
of the dielectric material. In embodiments of this invention, the
dielectric material is a semiconducting material. The dielectric constant
of the semiconducting material in the metal/semiconductor interfacial
region is controllably adjusted by adjusting one or more of the
semiconductor plasma frequency, the concentration and effective mass of
free carriers, and the background high-frequency dielectric constant in
the interfacial region. Thermal heating and/or voltage-gated
carrier-concentration changes may be used to variably adjust the value of
the semiconductor dielectric constant. |