Patent ID: 8009356
Filing Date: 2011-08-30
Classification: G02B

Abstract:
1. A tunable optical filter, comprising: a substrate, the substrate having a front side and a back side and being transparent at a light transmission wavelength; a doped region of the substrate, wherein the doped region has a doping level suitable for resistive heating by passage of a current; a metallic extraordinary optical transmission grating located proximate the front side of the substrate and having a periodic array of apertures therethrough, the apertures each having a maximum cross-sectional dimension less than the light transmission wavelength and a periodic spacing corresponding to approximately resonance with the light transmission wavelength; a dielectric layer within an evanescent-field distance of the extraordinary optical transmission grating and with a temperature-dependent dielectric constant, the dielectric layer being situated for heating as a consequence of the passage of the current through the doped region of the substrate, whereby the periodic array of apertures and the temperature-dependent dielectric constant produce a tuned surface plasmon passband at approximately the light transmission wavelength; and at least one contact in electrical contact with the doped region.