The disclosure relates to a method for forming a low refractive index layer on a substrate. The method generally includes (a) applying a block copolymer layer on a substrate, the block copolymer including a polar polymeric block and a non-polar polymeric block; (b) swelling the block copolymer layer with a solvent to increase the block copolymer layer thickness; (c) depositing a metal oxide or metalloid oxide layer on polar polymeric blocks of the block copolymer layer; and (d) removing the block copolymer layer from the substrate, thereby forming a porous metal oxide or metalloid oxide layer on the substrate.

A color filter unit includes an upper substrate, a color filter layer on a lower surface of the upper substrate, and a quantum dot layer on a lower surface of the color filter layer and including a quantum dot layer material and an arrangement assistant defining a space in which the quantum dot layer material is arranged.

A transmissive diffraction grating for a phase-stepping measurement system for determining an aberration map for a projection system comprises an absorbing layer. The diffraction grating is for use with radiation having a first wavelength (for example (EUV radiation). The absorbing layer is provided with a two-dimensional array of through-apertures. The absorbing layer is formed from a material which has a refractive index for the radiation having the first wavelength in the range 0.% to 1.04.

A form birefringent optical element includes a structured layer and a dielectric environment disposed over the structured layer. At least one of the structured layer and the dielectric environment includes a nanovoided polymer, the nanovoided polymer having a first refractive index in an unactuated state and a second refractive index different than the first refractive index in an actuated state. Actuation of the nanovoided polymer can be used to reversibly control the form birefringence of the optical element. Various other apparatuses, systems, materials, and methods are also disclosed.

A coating for an optical article, such as a lens, includes a bottom coating having at least one hydrophilic resin binder and at least one surfactant, forming an anti-fogging layer, and a top coating overlying the bottom coating, forming an anti-reflective layer. The top coating includes nanopores, which may be less than 150 nm in size.

A dielectric film is provided on a transparent substrate. The dielectric film has at least one low refractive index layer. An uppermost layer of the dielectric film contains SiO.sub.2 and has a film density of 92% or more. The uppermost layer contains an element having an electronegativity smaller than Si.

Provided is a subminiature wavelength tunable liquid crystal etalon filter capable of minimizing damage during manufacturing, a light source and an optical transceiver including the same. According to one aspect of the present embodiment, a wavelength tunable liquid crystal etalon filter capable of minimizing damage that may be applied to a seal line during a curing process and a light source and an optical transceiver including the same are provided.

The disclosure relates to a method for forming a low refractive index layer on a substrate. The method generally includes (a) applying a block copolymer layer on a substrate, the block copolymer including a polar polymeric block and a non-polar polymeric block; (b) swelling the block copolymer layer with a solvent to increase the block copolymer layer thickness; (c) depositing a metal oxide or metalloid oxide layer on polar polymeric blocks of the block copolymer layer; and (d) removing the block copolymer layer from the substrate, thereby forming a porous metal oxide or metalloid oxide layer on the substrate.

The present invention is directed to a chromatic effect light reflective unit (1; 1a-1g). The unit (1; 1a-1g) comprises a reflective layer (10) having at least one reflective surface (11), and a chromatic diffusion layer (20) having a first surface (21) proximal to the reflective surface (11) and a second surface (23), opposite and substantially parallel to the first, configured to be illuminated by incident light, wherein the chromatic diffusion layer (20) comprises a nano-pillar (70) or nano-pore (30) structure in a first material having a first refractive index (n1), immersed in a second material having a second refractive index (n2) other than the first (n1), in which the first and second materials are substantially non-absorbing or transparent to electromagnetic radiations with wavelength included in the visible spectrum, wherein the ratio (n.sub.M/n.sub.m) between a higher refractive index (n.sub.M) and a lower refractive index (n.sub.M) chosen between the first (n1) and the second (n2) refractive indexes is comprised between 1.05 and 3, wherein the nano- pillars (71) or nano-pores (31) have a development along a main direction not parallel to the first surface (21) and the second surface (23) of the chromatic diffusion layer and the nano- pillars (70) or nano-pores (30) structure is characterized by a plurality of geometric parameters comprising a pillar diameter or pore diameter (d.sub.p), a pillar length or pore length (1.sub.p) along said main development direction, and a surface density of nano-pillars or nano-pores (D.sub.p) and/or a structure (30,70) porosity (P.sub.p) and wherein the pillar diameter or pore diameter (d.sub.p) is comprised between 40 nm and 300 nm, the length (l.sub.p) along the main development direction is comprised between 300 nm and 40 .Math.m (300 nm < l.sub.p < 40 .Math.m) and at least one between the surface density of nano-pillars or nano-pores (D.sub.p) and the structure (30,70) porosity (P.sub.p) is configured to provide a higher regular reflectance for wavelengths of incident light comprised in the range of red with respect to wavelengths of incident light comprised in the range of blue and a higher diffuse reflectance for wavelengths of incident light comprised in the range of blue than wavelengths of incident light comprised in the range of red.

The present invention relates to broadband and tunable infrared (IR)-blocking optical filters for millimeter and sub-millimeter astronomy composed of small diffusely scattered particles embedded in an aerogel substrate. The size of the scattering particles included in the aerogel filters can be tuned to give variable cutoff frequencies. In one embodiment, the aerogel scattering optical filters of the present invention have ultra-low density and index of refraction (typically n<1.15), removing the need for anti-reflection coatings that limit bandwidth and increase filter complexity, and allowing for high transmission across an ultra-broad band from zero frequency to above 1 THz, and as much as 10 THz.