A broadband mirror, polarizer, or other reflector includes separate stacks of microlayers. Microlayers in each stack are arranged into optical repeat units, and the stacks are arranged in series. At a design angle of incidence such as normal incidence, the second stack provides a second 1.sup.st order reflection band and a distinct second 2.sup.nd order reflection band with a second spectral pass band therebetween. The first stack provides a first 1.sup.st order reflection band that fills the second spectral pass band such that a single wide reflection band is formed that includes the first 1.sup.st order reflection band, the second 1.sup.st order reflection band, and the second 2.sup.nd order reflection band. In some cases, the single wide reflection band can include a first 2.sup.nd order reflection band of the first stack. In some cases, the first and second stacks may have apodized portions which monotonically deviate from respective baseline portions.

A broadband partial reflector includes a first multilayer polymeric optical film having a total number of optical repeating units from a first side to a second side of the first multilayer polymeric optical film and a second multilayer polymeric optical film having a total number of optical repeating units from a first side to a second side of the second multilayer polymeric optical film and an intermediate layer on the second side of the multilayer polymeric optical film separates the first multilayer polymeric optical film from the second multilayer polymeric optical film. The first multilayer polymeric optical film has a first baseline optical repeating unit thickness profile and a first apodized optical repeating unit thickness profile monotonically deviating from the first baseline optical repeating unit thickness profile and defining the second side of the first multilayer polymeric optical film. The second multilayer polymeric optical film has a second baseline optical repeating unit thickness profile and a second apodized optical repeating unit thickness profile monotonically deviating from the second baseline optical repeating unit thickness profile and defining the first side of the second multilayer polymeric optical film.

An interference filter includes a transmissive first substrate including a first inner surface and a first outer surface facing each other, in which the first inner surface is provided with a first reflection film, a transmissive second substrate including a second inner surface and a second outer surface facing each other, in which the second inner surface is provided with a second reflection film, a first bonding portion configured to bond the first inner surface and the second inner surface to each other, and seal a first inner space between the first substrate and the second substrate, a transmissive third substrate facing the first outer surface, a second bonding portion configured to bond the first outer surface and the third substrate to each other, and seal a second inner space between the first substrate and the third substrate, a transmissive fourth substrate facing the second outer surface, and a third bonding portion configured to bond the second outer surface and the fourth substrate to each other, and seal a third inner space between the second substrate and the fourth substrate, wherein the first inner space, the second inner space, and the third inner space are lower in pressure than atmospheric pressure.

Multi-layer optical films that can be utilized as polarizer or mirror films and can be incorporated into optical stacks. The optical film includes a plurality of alternating polymeric first and second interference layers numbering greater than 50 and disposed between, and integrally formed with, first and second skin layers, each of the first and second interference layers has an average thickness less than 250 nm. The first and second interference layers and the first and second skin layers are compositions that include polyester.

Light shielding articles are provided. Light shielding articles include a first multilayer optical film comprised of alternating first and second polymeric optical layers collectively reflecting at an incident light angle of at least one of 0, 15, 30, 45, 60, or 75, an average of at least 70, 80, 90, or 95 percent of incident visible light over at least a wavelength range from 400 nanometers (nm) to 700 nm. The light shielding articles further include either a second multilayer optical film or a barrier coating disposed on the first multilayer optical film. The light shielding article transmits at an incident light angle of at least one of 0, 15, 30, 45, 60, or 75, an average of at least 70, 80, 90, or 95 percent of incident radio frequency waves in at least one wavelength range from 1 mm to 10 mm, 10 mm to 100 mm, or 100 mm to 1000 mm. Additionally, an electromagnetic receiver and/or emitter is provided that includes a light shielding article according attached to at least a portion of the electromagnetic receiver and/or emitter.

A composite cooling film comprises an ultraviolet-reflective multilayer optical film and a reflective microporous layer secured thereto. The ultraviolet-reflective multilayer optical film is at least 50 percent reflective of ultraviolet radiation over a majority of the wavelength range of at least 340 but less than 400 nanometers. The reflective microporous layer has a continuous phase comprising a nonfluorinated organic polymer and is diffusely reflective of solar radiation over a majority the wavelength range of 400 to 2500 nanometers, inclusive. The composite cooling film has an average absorbance over the wavelength range of 8 to 13 microns of at least 0.85. An article comprising the composite cooling film adhered to a substrate is also disclosed.

Optical films are described. In particular, optical films including a reflective polarizer portion and an infrared portion, with no adhesive between these two portions, are described. These optical films may be particularly suitable for combiner applications, including automotive heads up display applications with demanding ambient environments.

An example liquid mirror includes a first liquid, a second liquid immiscible with the first liquid and configured to define an interface between the first liquid and the second liquid, and a plurality of reflective particles configured to self-assemble at the interface between the first liquid and the second liquid. The liquid mirror also includes a support structure defining an outer surface configured to support the first liquid and the second liquid. The outer surface, the first liquid, and the second liquid are configured to cause the plurality of reflective particles to form a focusing shape via capillary action of the first liquid and the second liquid and interaction with the support structure.

A display system for imaging a user body portion includes a display panel, an optical sensor disposed on the display panel and configured to detect light reflected by the user body portion, and an optical stack disposed between the display panel and the optical sensor. The optical stack includes a first optical reflector and a light collimating film. The light collimating film includes a plurality of substantially coplanar alternating first and second regions. For an incident light, a visible wavelength range, and an infrared wavelength range, and for each of a first incident angle of less than about 5 degrees and a second incident angle of between about 40 degrees and about 70 degrees, the plurality of polymeric layers has an average optical reflectance of greater than about 70% in the visible wavelength range and an optical transmittance of greater than about 30% in the infrared wavelength range.

To provide a mirror and a head-up display apparatus which can be manufactured more easily with high shape accuracy. A mirror reflects display light L and has a reflective curved surface forming a curved surface. The mirror includes: a base material with an attachment surface forming a curved surface; a mirror film that forms the reflective curved surface in a state of being bonded to the attachment surface; and reference protrusions 24a, 24b, and 24c formed to protrude around the base material. The reference protrusions 24a, 24b, and 24c each includes an upper surface and a side surface. The upper surfaces of the reference protrusions 24a and 24b are located on a same plane Pxz. The side surfaces of the reference protrusions 24a and 24c are located on a same plane Pyz. The planes Pxz and Pyz are virtual planes orthogonal to each other.