The present invention relates to an attenuator for a light source that has a monochromatic output, and in particular a variable attenuator for such a source.

Light wave separation lattices and methods of formation are provided herein. In some embodiments, a light wave separation lattice includes a first layer having the formula RO.sub.xN.sub.y, wherein the first layer has a first refractive index; and a second layer, different from the first layer, disposed atop the first layer, and having the formula R′O.sub.xN.sub.y, wherein the second layer has a second refractive index different from the first refractive index, and wherein R and R′ are each one of a metal or a dielectric material. In some embodiments, a method of forming a light wave separation lattice includes depositing a first layer having a predetermined desired refractive index atop a substrate by a physical vapor deposition process; and depositing a second layer, different from the first layer, atop the first layer, wherein the second layer has a predetermined second refractive index different from the first refractive index.

An optical assembly including an optical element insert molded directly onto an optical stack is provided. The optical stack includes an optical film and may include a liner with the optical film being disposed between the optical element and the liner. The liner, if included, is removable from the optical film without substantial damage to the optical film. An outermost layer of the optical film may be diffusion bonded to a major surface of the optical element. The optical film includes a protective coating having an average thickness of no more than 30 micrometers. The protective coating includes an at least partially cured composition. The composition includes 70 to 96 weight percent of urethane (meth)acrylate compound having an average (meth)acrylate functionality of 2 to 9.5, and 2 to 20 weight percent of (meth)acrylate monomer having a (meth)acrylate functionality of 1 to 2.

A coated article may comprise a substrate and an optical coating. The substrate may have a major surface comprising a first portion and a second portion. A first direction that is normal to the first portion of the major surface may not be equal to a second direction that is normal to the second portion of the major surface. The optical coating may be disposed on at least the first portion and the second portion of the major surface. The coated article may exhibit at the first portion of the substrate and at the second portion of the substrate hardness of about 8 GPa or greater at an indentation depth of about 50 nm or greater as measured on the anti-reflective surface by a Berkovich Indenter Hardness Test.

An optical filter includes: an absorption layer including a first near-infrared absorbing dye (D1), a second near-infrared absorbing dye (D2), and a transparent resin; and a reflection layer including a dielectric multilayer film. The dye (D1) and the dye (D2) are squarylium compounds satisfying following (1) to (3). (1) The dye (D1) has a maximum absorption wavelength λ.sub.max(D1) within a range of 680 to 730 nm, and the difference between a wavelength at which a transmittance is 80% on the shorter wavelength side than λ.sub.max(D1) when the concentration is adjusted such that a transmittance at λ.sub.max(D1) is 10%, and λ.sub.max(D1) is 100 nm or less. (2) The dye (D2) has a maximum absorption wavelength λ.sub.max(D2) within a range of 720 to 770 nm. (3) A value obtained by subtracting λ.sub.max(D1) from λ.sub.max(D2) is 30 nm or more and 85 nm or less.

A Fabry-Perot interference filter includes: a substrate having a first surface and a second surface facing each other; a first layer structure disposed on the first surface; and a second layer structure disposed on the second surface, wherein the first layer structure is provided with a first mirror portion and a second mirror portion facing each other with an air gap therebetween, and a distance between the first mirror portion and the second mirror portion is varied, and the second layer structure is formed with a separation region separating at least a part of the second layer structure into one side and another side in a direction along the second surface.

An optical filter includes a plurality of optical channels that each have a Fano resonance characteristic. A first optical channel, of the plurality of optical channels, is configured to pass a first portion of a first set of light beams (that are associated with a first wavelength range) and reflect a second portion of the first set of light beams when the first set of light beams falls incident on a particular surface of the first optical channel. A second optical channel, of the plurality of optical channels, is configured to pass a first portion of a second set of light beams (that are associated with a second wavelength range) and reflect a second portion of the second set of light beams when the second set of light beams falls incident on a particular surface of the second optical channel.

A hybrid optical filter includes a plurality of film layers laminated to one another. This renders the filter flexible enough to be bendable and to implement a combination of at least two different wavelength-dependent optical filtering properties in a single hybrid optical filter. Two or more of the optical filtering properties may be caused by interference-based blocking of different ranges of wavelengths of light. Additionally or alternatively, at least one of the optical filtering properties may be an absorptive blocking of a first range of wavelengths of light and at least another one of the optical filtering properties is an interference-based blocking of a second range of wavelengths of light. The first range of wavelengths and the second range of wavelengths may overlap to provide for customized ranges of blocked wavelengths.

A hybrid optical filter includes a plurality of film layers laminated to one another. This renders the filter flexible enough to be bendable and to implement a combination of at least two different wavelength-dependent optical filtering properties in a single hybrid optical filter. Two or more of the optical filtering properties may be caused by interference-based blocking of different ranges of wavelengths of light. Additionally or alternatively, at least one of the optical filtering properties may be an absorptive blocking of a first range of wavelengths of light and at least another one of the optical filtering properties is an interference-based blocking of a second range of wavelengths of light. The first range of wavelengths and the second range of wavelengths may overlap to provide for customized ranges of blocked wavelengths.

A light detecting device is provided with: a filter array including filters arranged two-dimensionally, each of the filters having a light-incident surface and a light-emitting surface, the filters including multiple types of filters having mutually different transmission spectra; and an image sensor having a light-detecting surface facing the light-emitting surface, the image sensor being provided with light-detecting elements arranged two-dimensionally on the light-detecting surface, wherein the distance between the light-emitting surface and the light-detecting surface is different for each of the filters.