The disclosed structure is configured such that it does not support electromagnetic waves having frequencies within a selected band gap; those electromagnetic waves are thus reflected. Some variations provide an omnidirectional infrared reflector comprising a three-dimensional photonic crystal containing: rods of a first material that has a first refractive index, wherein the rods are arranged to form a plurality of lattice periods in three dimensions, and wherein the rods are connected at a plurality of nodes; and a second material that has a refractive index that is lower than the first refractive index, wherein the rods are embedded in the second material. The lattice spacing and the rod radius or width are selected to produce a photonic band gap within a selected band of the infrared spectrum. Methods of making and using the three-dimensional photonic crystal are described. Applications include thermal barrier coatings and blackbody emission signature control.

A photonic reflector device includes a first layer, a second layer, and a third layer. The first layer, which functions as a retro-reflector, is formed of a first material contacting a second material and having a non-planar interface therebetween. The second layer, which functions as a photonic crystal, includes third and fourth materials that have different refractive indices from one another and are configured such that the second layer has a periodic optical potential along at least one dimension. The third layer, which functions as a Lambertian scatterer, includes a plurality of inclusions in a first matrix material. In combination, the layers may be optimized to synergistically reflect targeted wavelengths and/or polarizations of light.

A photonic crystal film, a method for manufacturing the photonic crystal film, and an anti-forgery article comprising the photonic crystal film are disclosed. The photonic crystal film includes a polyurethane-based polymer matrix and colloidal particles dispersed in the polyurethane-based polymer matrix and arranged in a crystal lattice structure. The colloidal particles includes one or more selected from metal nanoparticles, metal oxide nanoparticles, organic nanoparticles, and carbon structure nanoparticles.

An anti-forgery color conversion film includes a photonic crystal structure whose color is converted by an external stimulus such as a breath. The photonic crystal structure includes a first refractive index layer including a first polymer exhibiting a first refractive index; and a second refractive index layer which is alternately laminated with the first refractive index layer and includes a second polymer exhibiting a second refractive index. A consumer who purchases an article including the color conversion film may easily distinguish the authenticity of the article.

A system, method and device for use as a reflector for a light emitting diode (LED) are disclosed. The system, method and device include a first layer designed to reflect transverse-electric (TE) radiation emitted by the LED, a second layer designed to block transverse-magnetic (TM) radiation emitted from the LED, and a plurality of ITO layers designed to operate as a transparent conducting oxide layer. The first layer may be a one-dimension (1D) distributed Bragg reflective (DBR) layer. The second layer may be a two-dimension (2D) photonic crystal (PhC), a three-dimension (3D) PhC, and/or a hyperbolic metamaterial (HMM). The 2D PhC may include horizontal cylinder bars, vertical cylinder bars, or both. The system, method and device may include a bottom metal reflector that may be Ag free and may act as a bonding layer.

A photonic crystal, a light conversion device, a display panel, and a pair of glasses are provided. The photonic crystal of the embodiment of the present disclosure includes first dielectric layers and second dielectric layers having different refractive indexes, and the first dielectric layers and the second dielectric layers are alternately stacked. A thickness and a refractive index of each of the first dielectric layers and a thickness and a refractive index of each of the second dielectric layers are configured such that the photonic crystal blocks blue light with a wavelength of 420 nm to 470 nm incident into the photonic crystal from passing through the photonic crystal.

A robust conjugate symmetric optical apparatus is disclosed. The robust conjugate symmetric optical apparatus comprises a first optical cell set and a second optical cell set. The first optical cell set includes a first plurality of cells, each of which includes a first left half cell and a first right half cell, and the respective first right half cell and the corresponding first left half cells form a first symmetric structure therebetween. The second optical cell set includes a second plurality of cells, each of which includes a second left half cell and a second right half cell, and the respective second right half cell and the corresponding second left half cells form a second symmetric structure therebetween, wherein each of the first left half cells of the first optical cell set and each of the second right half cells of the second optical cell set have the same structure; and each of the first right half cells of the first optical cell set and each of the second left half cells of the second optical cell set have the same structure.

A multilayer film and a preparation method thereof is provided, and belongs to the technical field of optical films. The provided multilayer film comprises an ultraviolet blocking material and a cholesteric liquid crystal layer. The cholesteric liquid crystal layer comprises a polymerizable liquid crystal monomer, a polymerizable chiral dopant and a photoinitiator. The multilayer film can filter ultraviolet rays and near infrared rays in natural light, thereby reducing the heat effect of the natural light and harms of the ultraviolet rays to people and objects. In addition, the multilayer film has a high visible light transmission rate, which does not distort the color of the natural light passing through.

A two-dimensional topological photonic crystal cavity, a design method thereof and an application in a laser. The two-dimensional topological photonic crystal cavity comprises multiple photonic crystal supercells, the multiple photonic crystal supercells having vortex-shaped structural variation around a center of the two-dimensional topological photonic crystal cavity, and bands of the multiple photonic crystal supercells having Dirac points at balance positions of the vortex-shaped structural variation. The two-dimensional topological photonic crystal cavity, also called the Dirac vortex cavity, is characterized by having large mode field area, large free spectral range, narrow beam divergence angle, arbitrary mode degeneracy and compatibility with plurality of types of substrate material, and may be used in a surface-emitting semiconductor laser, enabling stable single-transverse-mode and single-longitudinal-mode operation, while ensuring broad-area and high-power output of a laser.

The present invention provides a sensing device for detecting an analyte containing a non-metallic element such as F. A working sensor has a 3D array of voids each having a void internal wall. The void internal walls have cavities each having a cavity internal wall made from a material containing the non-metallic element. A binding of the analytes to the cavities induces a detectable variation of the optical property of the 3D array of voids. The invention exhibits numerous technical merits such as high sensitivity, high specificity, fast detection, ease of operation, low power consumption, zero chemical release, and low operation cost, among others.