Document Type



A flat panel color display is provided in which white collimated light incident on a light coupling means having a metal layer and a liquid crystal layer formed on a surface of the coupling means produces a colored spot of light at the interface of the metal layer and liquid crystal layer through the excitation of surface plasmons. The present invention utilizes the color selective scattering of incident white light by surface plasmons and includes a coupling device, such as a high index glass prism, with a metal film layer and a liquid crystal layer formed on the coupling device. Surface plasmon waves can be generated at a negative dielectric (metal layer)-positive dielectric (liquid crystal layer) interface when the dispersion relationship is satisfied. The incident white light includes photons which have frequencies approximately equal to the plasmon resonance, and such photons are strongly scattered. Photons having a frequency other than the plasmon resonance will be totally reflected. The dispersion relationship of the metal-liquid crystal interface depends on the dielectric constant of the metal, which is not typically variable, and the dielectric constant of the liquid crystal, which is variable. An external voltage control/modulator may be used to vary the dielectric constant of the liquid crystal, thereby controlling the plasmon resonance condition and the frequencies (color) of the scattered photons.

Patent Country


Patent Number


Publication Date



The University of Toledo

Application Number


Filing Date

October 1993

Primary Class


Secondary Class

345/32; 349/1; 349/62


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The University of Toledo


University of Toledo Libraries

Digital Publisher

Digital Initiatives