A 3D printed GRIN device, the formulation and the method for making the GRIN device are disclosed. The GRIN (graded-index) device comprises i) a first phase comprising at least one polymer; ii) a second phase comprising at least one first component; and, optionally, iii) an interface between the first phase and the second phase, wherein the interface has a concentration gradient of the at least one first component, whereby the concentration of the at least one first component decreases with distance away from the second phase towards the first phase, wherein the at least one first component comprises at least one functional component, at least one functional precursor component, or combinations thereof, and wherein the GRIN device is a functional GRIN device, a functional precursor GRIN device, or a combination of a functional and functional precursor GRIN device.

A magnetic pigment flake includes a filtering film layer, with magnetic or magnetizable material, and a metal nanoparticles layer, formed on a surface of the filtering film layer. The metal nanoparticles layer is configured to generate scattered light enhanced by a local surface plasmon resonance under an irradiation of visible light exceeding a predetermined intensity. An optically variable ink includes an ink body and the above-mentioned magnetic pigment flakes. An anti-falsification article includes an article body and the above-mentioned optically variable ink. The magnetic pigment flake of the optically variable ink is magnetically oriented, such that a bright and dark areas are generated with a viewing angel changing under an irradiation of visible light below the predetermined intensity. Under an irradiation of visible light exceeding the predetermined intensity, light with a color different from that of the bright area is generated on a corresponding position of the dark area.

A light-emitting diode includes a first semiconductor region of one of p- or n-conductivity types, a second semiconductor region of the other one of p- or n-conductivity types, forming a p-n junction with the first semiconductor region, and a quantum well layer at the p-n junction between the first and second semiconductor regions. A hyperbolic metamaterial structure is provided in the second semiconductor region. The hyperbolic metamaterial structure is coupled to the quantum well layer for extracting light from the quantum well layer. The hyperbolic metamaterial structure may be patterned to provide an array of nanoantennas to apodize the emitted beam, and to control the polarization state of the emitted beam.

As described above, one or more aspects of the present disclosure provide articles having structural color, and methods of making articles having structural color.

Provided herein are systems and methods for performing assays. In particular, provided herein are systems and methods for performing sensitive and rapid immunoassays.

The present invention relates to an optical nanostructure sensing device and an image analysis method. The image analysis method includes: illuminating a light beam from a predetermined incident angle onto a nanostructure pixel sensor; capturing images of the nanostructure pixel sensor when applying an analyte on the nanostructure pixel sensor; obtaining a relationship of periodic spacing and brightness from each of the images; and obtaining wavelength values from the relationship of periodic spacing and brightness at a predetermined brightness value; and determining a sensing process based on a wavelength shift of the wavelength values. The nanostructure pixel sensor includes a plurality of the nanostructure pixels, each of the nanostructure pixels includes periodic nanostructures, and the relationship of periodic spacing and brightness is based on the brightness of the nanostructure pixels having different periodic spacings.

Novel directional antennas are disclosed which utilize plas-monic surfaces (PS) that include or present an array of closely-spaced parasitic antennas, which may be referred to herein as “parasitic arrays” or fractal plasmonic arrays (FPAs). These plasmonic surfaces represent improved parasitic directional antennas relative to prior techniques and apparatus. Substrates can be used which are transparent and/or translucent.

Devices and techniques are provided for achieving OLED devices that include one or more enhancement layers formed at least partially from a plasmonic material exhibiting surface plasmon resonance that non-radiatively couples to an organic emissive material in the organic emissive layer, where a majority of excited state energy is transferred from the organic emissive material to a non-radiative mode of surface plasmon polaritons of the enhancement layer.

A circular polarization filter of a chiral metasurface structure is disclosed including a substrate having a nanograting pattern extending from the substrate, a dielectric layer formed directly on the nanograting pattern, and a plasmonic structure in direct contact with the dielectric layer, where the plasmonic structure may be oriented at a nonzero angle with respect to the nanograting pattern. An integrated polarization filter array is also disclosed including include a linear polarization filter, and a circular polarization filter. Methods of detecting full-stokes polarization using an integrated polarization filter array having both linear and circular polarization filters made from chiral metasurface structures is disclosed. Methods of using a Mueller matrix to evaluate polarization response of any optical device or system is also disclosed.

A plasmonic device is disclosed, the plasmonic device having a base substrate and an electrically conductive film formed on the base substrate. The base substrate has a reference upper surface and an arrangement of chiral nanostructures formed in relief from the reference upper surface. Each chiral nanostructure has a nanostructure upper surface which is disposed at a distance of at least 30 nm from the reference upper surface in a thickness direction. The electrically conductive film is formed on the nanostructure upper surface of each chiral nanostructure and on at least part of the reference upper surface of the base substrate. Also disclosed is a method of analysis of a biological material using the plasmonic device, by depositing the biological material onto the plasmonic device and irradiating the plasmonic device and the biological material with electromagnetic radiation. The arrangement of chiral nanostructures and electrically conductive film generates a superchiral electromagnetic field, the effect of the presence of the biological material on the superchiral electromagnetic field then being detected.