A method for measuring a refractive index of a medium includes exciting a first antisymmetric resonance of a first metasurface, including a first periodic array of resonators formed on a substrate surface, with illumination incident on the first metasurface at a non-normal incidence angle with respect to the substrate surface, the first metasurface including the medium encapsulating the first periodic array of resonators. The method also includes determining a refractive index of the medium from a first amplitude of a first transmitted signal that includes a portion of the illumination transmitted through the first metasurface.

A colorimetric sensor for detecting an analyte of interest that includes multiple surfaces and a molecularly imprinted polymer defining a cavity shaped to receive an analyte of interest. Each surface defines a void (e.g., a pore or a nanohole) and at least one surface defines a fluid inlet. The sensor is configured such that, when an analyte contacts the molecularly imprinted polymer and becomes disposed within the cavity, a wettability of at least one of the surfaces changes thereby to cause a detectable color change in the sensor. Optionally, the sensor may also include a metal layer at a bottom of each void or nanohole and outside a top of each void or nanohole for use as a plasmon resonance-type sensor.

Provided are a front light source and a display apparatus. The front light source is disposed on a light emitting side of a display panel. The front light source includes: a light guide member and a light emitting member disposed on a light incident side of the light guide member, the light guide member being configured to guide light emitted by the light emitting member onto the display panel; the light emitting member includes: a light source element and a quantum dot element which are disposed on a same layer, the light source element being configured to emit light of a first color, and the quantum dot element being configured to emit light of three colors including three-primary colors under excitation of the light emitted by the light source element, the first color is one of the three-primary colors.

A colloidal crystal structure includes a colloidal crystal layer including a plurality of colloidal particles and a binder disposed between the plurality of colloidal particles to fix the colloidal particles, and a refractive index control material that is provided on one surface of the colloidal structural layer, is transparent, and has a refractive index difference of less than 10% with respect to the binder. A light-emitting device includes an optical filter including the colloidal crystal structure, and a light source, and a part of primary light emitted by the light source passes through the optical filter. A lighting system includes the light-emitting device.

Polymer-infiltrated nanoparticle films (PINFs) that have high volume fractions (>50 vol %) of nanoparticles (NPs) possess enhanced properties making them ideal for various applications. Capillary rise infiltration (CaRI) of polymer and solvent-driven infiltration of polymer (SIP) into pre-assembled NP films have emerged as versatile approaches to fabricate PINFs. Although these methods are ideal for fabricating PINFs with homogenous structure, several applications including separations and photonic/optical coatings would benefit from a method that enables scalable manufacturing of heterostructured (i.e., films with variation in structural properties such as porosity, composition, refractive indices etc.) PINFs. In this work, a new technique is developed for fabricating heterostructured PINFs with cavities based on CaRI. A bilayer composed of densely packed inorganic NP layer atop polymer NP layer is thermally annealed above the glass transition temperature of the polymer NP, which induces CaRI of the polymer into the interstices of the inorganic NP layer. Exploiting the difference in the sizes of the two particles, heterostructured double stack PINFs composed of a PINF and a layer with large cavities are produced at a moderate temperature (<200° C.). Using these heterostructured PINFs, Bragg reflectors that can detect the presence of wetting agents in water are fabricated.

The present invention discloses a method for preparing a sodium interface and a method for preparing a sodium-based optical structure device. This sodium interface is prepared in an inert gas atmosphere by the following steps: (1) melting solid sodium metal into liquid by heat, and stripping off solid oxides and impurities on the surface of the molten sodium metal to obtain pure liquid sodium with metallic luster; and (2) spin-coating a dielectric substrate with the liquid sodium to obtain the sodium interface tightly attached to the dielectric substrate. The prepared sodium interface can be used as a plasmon polariton material for use in plasmon polariton optical waveguides, nano-lasers and the like.

Polymer composite photonic crystal materials are disclosed as coatings which have high reflection (>30%) in a specific range of the electromagnetic spectrum, such as ultraviolet (<400 nm), visible (Vis, 400 nm-700 nm), or near-infrared radiation range (NIR, 700-2000 nm), and relatively low reflection (<20% reflection) in a second, different range of the electromagnetic spectrum. Surprisingly, it was found that through a formulation and additives approach, the optical properties of polymer composite photonic crystal films can be selectively modified from a variety of different coating methods, including spray deposition.

Polymer composite photonic crystal materials are disclosed as coatings with topcoats having high reflection (>30%) in a specific range of the electromagnetic spectrum, such as ultraviolet (<400 nm), visible (Vis, 400 nm-700 nm), or near-infrared radiation range (NIR, 700-2000 nm), and optionally a relatively low reflection (<20% reflection) in a second, different range of the electromagnetic spectrum. Surprisingly, it was found that through a multi-layer coating approach, the optical properties of polymer composite photonic crystal films can be selectively modified from a variety of different coating methods, including spray deposition.

A quantum dot color filter substrate includes a substrate, a color filter layer, a quantum dot film layer, and a transparent conductive layer disposed between the color filter layer and the quantum dot film layer. The transparent conductive layer is externally connected to a power module to form a closed circuit. When a voltage is applied to the transparent conductive layer, the transparent conductive layer may generate heat, which can quickly remove solvents in a quantum dot film layer.

A system and a method for a nanostructured film including a first layer for reflecting at least a portion of an electromagnetic radiation and a second layer for receiving the remainder of the electromagnetic radiation through the first layer and subsequently reflecting at least a portion of the received electromagnetic radiation through the first layer, wherein two electromagnetic radiations with the same wavelength reflected by the first and second layers respectively are combined to form a strengthened electromagnetic radiation, the wavelength of the strengthened electromagnetic radiation being variable based on the physical property of the first layer.