The absorbance or emission wavelength of composite materials comprising a transition metal doped shell disposed over a rare earth doped core and a functionalizable group on the surface of the transition metal doped shell can change upon subjection to a carboxylic acid. This method of changing the absorbance or emission wavelength of a composite material can be used to identify counterfeit currency using an ink comprising a composite material.

Articles comprises iron oxide colloidal nanocrystals arranged within chains, wherein the chains of nanocrystals are embedded within a material used to form the article or a transfer medium used to transfer a color to the article are described. The material or transfer medium includes elastic properties that allow the nanocrystals to display a temporary color determined by the strength of an external force applied to the article, and the material or transfer medium includes memory properties that cause the displayed temporary color to dissipate when the external force is removed, wherein the dissipation of the displayed temporary color is sufficiently slow as to be visually observable by an average observer's unaided eye.

An optical modulator may include a lower waveguide, an upper waveguide, and a dielectric layer disposed therebetween. When a voltage potential is created between the lower and upper waveguides, these layers form a silicon-insulator-silicon capacitor (also referred to as SISCAP) guide that provides efficient, high-speed optical modulation of an optical signal passing through the modulator. In one embodiment, at least one of the waveguides includes a respective ridge portion aligned at a charge modulation region which may aid in confining the optical mode laterally (e.g., in the width direction) in the optical modulator. In another embodiment, ridge portions may be formed on both the lower and the upper waveguides. These ridge portions may be aligned in a vertical direction (e.g., a thickness direction) so that ridges overlap which may further improve optical efficiency by centering an optical mode in the charge modulation region.

A method for constructing a solar rectenna array by growing carbon nanotube antennas between lines of metal, and subsequently applying a bias voltage on the carbon nanotube antennas to convert the diodes on the tips of the carbon nanotube antennas from metal oxide carbon diodes to geometric diodes. Techniques for preserving the converted diodes by adding additional oxide are also described.

A method for constructing a solar rectenna array by growing carbon nanotube antennas between lines of metal, and subsequently applying a bias voltage on the carbon nanotube antennas to convert the diodes on the tips of the carbon nanotube antennas from metal oxide carbon diodes to geometric diodes. Techniques for preserving the converted diodes by adding additional oxide are also described.

An apparatus is described that selectively absorbs electromagnetic radiation. The apparatus includes a conducting surface, a dielectric layer formed on the conducting surface, and a plurality of conducting particles distributed on the dielectric layer. The dielectric layer can be formed from a material and a thickness selected to yield a specific absorption spectrum. Alternatively, the thickness or dielectric value of the material can change in response to an external stimulus, thereby changing the absorption spectrum.

The present invention generally relates to an extraction structure for a UV lighting element. The present invention also relates to a UV lamp comprising such an extraction structure onto a substrate. The extraction structure comprises a plurality of nanostructures for anti-reflecting purposes. The nanostructures are grown on the top surface of at least one of the first and second side of the substrate.

Implementations of light filters for use in cryptographic operations may include: a substrate having at least a first side and a second side, the first side opposing the second side, the substrate including one of a translucent, a transparent, and a semi-transparent material, and any combination thereof; and one or more layers of microscopic structures coupled to one of the first side, the second side, and both the first side and the second side of the substrate, the microscopic structures each containing one or more structural elements configured to interact with light. The microscopic structures may be configured to collectively form a unique light pattern on a detector optically coupled with the light filter. The unique pattern may be configured to be used to form a challenge-response pair (CRP) and the CRP is configured to be used in cryptographic operations to authenticate an electronic device associated with the light filter.

A backlight unit for a liquid crystal display device including a liquid crystal panel, includes: a light source including a light-emitting diode (ED) which generates and emits light; and a light converting layer between the light source and the liquid crystal panel, spaced apart from the light source, and converting the light from the light source into white light and emitting the white light toward the liquid crystal panel. The light converting layer includes: semiconductor nanocrystals, and a barrier material which restricts penetration of moisture or oxygen.

Articles comprises iron oxide colloidal nanocrystals arranged within chains, wherein the chains of nanocrystals are embedded within a material used to form the article or a transfer medium used to transfer a color to the article are described. The material or transfer medium includes elastic properties that allow the nanocrystals to display a temporary color determined by the strength of an external force applied to the article, and the material or transfer medium includes memory properties that cause the displayed temporary color to dissipate when the external force is removed, wherein the dissipation of the displayed temporary color is sufficiently slow as to be visually observable by an average observer's unaided eye.