The present disclosure is directed to a thin-film element that enables analytes to be analyzed on separate surfaces. In an example, a thin-film element includes a first layer for processing a fluid sample to generate a first analyte and a second analyte. The thin-film element also includes a second layer configured to be impermeable to the first analyte to enable the first analyte to be retained by the first layer and permeable to the second analyte to enable the second analyte to pass through the second layer. The thin-film element further includes a third layer configured to retain the second analyte. The second layer includes a first reflective surface and a second reflective surface to provide reflectance signals indicative of analytes present in the first and third layers to sensors located on opposite sides of the thin-film element.

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 bandpass filter may include a set of layers. The set of layers may include a first subset of layers. The first subset of layers may include hydrogenated germanium (Ge:H) with a first refractive index. The set of layers may include a second subset of layers. The second subset of layers may include a material with a second refractive index. The second refractive index may be less than the first refractive index.

A light-receiving element, comprising a plurality of photodiodes formed by stacking in this sequence, a lower reflection mirror, a resonator including a photoelectric conversion layer, and an upper reflection mirror on a semiconductor substrate, wherein the plurality of photodiodes share the semiconductor substrate and the lower reflection mirror, the plurality of photodiodes includes a first photodiode having a resonance wavelength 1 and a second photodiode having a resonance wavelength 2 that is larger than the resonance wavelength 1, and a reflectance of the lower reflection mirror has a first peak corresponding to the resonance wavelength 1 and a second peak corresponding to the resonance wavelength 2.

Various embodiments disclosed relate to multilayer films including hidden fluorescent features. The present disclosure includes a multilayer optical film including an isotropic multilayer optical film having first and second opposed major surfaces. The isotropic multilayer optical film reflects at least 50% of a light that is at least one of ultraviolet light or visible light, having an incident angle less than a cutoff angle from normal to the first major surface of the isotropic multilayer optical film, wherein the cutoff angle is in a range from 10 to 70. The isotropic multilayer optical film allows at least 50% of the light having an incident angle of more than the cutoff angle from normal to the first major surface of the isotropic multilayer optical film to pass through the isotropic multilayer optical film. The isotropic multilayer optical film includes a marking on the second major surface of the isotropic multilayer optical film, the marking including at least one fluorescent compound. Various embodiments of multilayer optical films described herein are useful, for example, as anti-counterfeiting features, such as in identification documents or cards, currency, labels for pharmaceuticals or other high value products, or financial cards.

Provided is a dielectric multilayer film mirror including: a substrate; a first multilayer film structure formed on the substrate and including alternately stacked layers of a first low refractive index material having a refractive index equal to or lower than a refractive index of a second low refractive index material and a first high refractive index material having a refractive index higher than a refractive index of a second high refractive index material; and a second multilayer film structure formed on the first multilayer film structure and including alternately stacked layers of the second low refractive index material and the second high refractive index material, the second high refractive index material having a refractive index higher than a refractive index of the second low refractive index material and having an extinction coefficient lower than an extinction coefficient of the first high refractive index material.

An electronic device may include conductive structures having a visible-light-reflecting coating. The coating may include a seed layer, transition layers, a neutral-color base layer, and an uppermost layer that forms a single-layer interference film. The neutral-color base layer may be opaque to visible light. The interference film may include silicon and may have an absorption coefficient between 0 and 1. The interference film may include, for example, CrSiN or CrSiCN. The composition of the interference film, the thickness of the interference film, and/or the composition of the base layer may be selected to provide the coating with a desired color near the middle of the visible spectrum (e.g., at green wavelengths). The color may be relatively stable even if the thickness of the coating varies across its area.

Systems and methods for embodiments having an extra thick ultraviolet durability coating are described herein. For example, a system may include a laser block assembly. The system may also include a cavity in the laser block assembly. Further, the system may include a plurality of multilayer mirrors in the cavity. In certain embodiments, at least one multilayer mirror of the plurality of multilayer mirrors may include a plurality of alternating layers of a first optical material having a high index of refraction and a second optical material having a first low index of refraction. Additionally, the at least one multilayer mirror may include a multilayer durability coating disposed on the plurality of alternating layers.

The present invention provides an optical layered body having excellent blue light blocking properties without affecting the color tone of displayed images. Provided is an optical layered body having a structure including: a substrate; and one or two or more functional layers on at least one surface of the substrate, the optical layered body having a spectral transmittance at a wavelength of 380 nm of lower than 1%, a spectral transmittance at a wavelength of 410 nm of lower than 10%, and a spectral transmittance at a wavelength of 440 nm of 70% or higher.

A bandpass filter may include a set of layers. The set of layers may include a first subset of layers. The first subset of layers may include hydrogenated germanium (Ge:H) with a first refractive index. The set of layers may include a second subset of layers. The second subset of layers may include a material with a second refractive index. The second refractive index may be less than the first refractive index.