Abstract: The present disclosure provides a reflective polarizer including a plurality of polymeric first layers and a plurality of polymeric second layers. A plot of an average layer thickness versus a layer number for the pluralities of polymeric first, but not second, layers includes a knee region separating a left region including at least 50 sequentially arranged polymeric first layers. The polymeric first layers have lower layer numbers, and the average layer thickness increases with increasing layer number from a right region including at least 5 sequentially arranged polymeric first layers. The polymeric first layers have higher layer numbers and the average thickness increases with increasing layer number, such that linear fits to the at least 50 sequentially arranged polymeric first layers and to the at least 5 sequentially arranged polymeric first layers have respective positive slopes S1 and S2, S2/S1?5.

Abstract: Broadband visible reflectors are disclosed. In particular, broadband visible reflectors with reduced on-axis blue reflectivity are described. Broadband visible reflectors that appear yellow in reflection are described. Such broadband visible reflectors may be used in backlights and displays.

Abstract: Optical films are disclosed that include a plurality of interference layers. Each interference layer reflects or transmits light primarily by optical interference. The total number of the interference layers is less than about 1000. For a substantially normally incident light in a predetermined wavelength range, the plurality of interference layers has an average optical transmittance greater than about 85% for a first polarization state, an average optical reflectance greater than about 80% for an orthogonal second polarization state, and an average optical transmittance less than about 0.2% for the second polarization state.

Abstract: Optical films, such as reflective polarizer films, and optical systems including the optical films are described. An optical system includes one or more optical lenses having at least one curved major surface, a partial reflector, and a reflective polarizer. For a substantially normally incident light in a predetermined wavelength range extending at least from about 450 nm to about 600 nm: the partial reflector has an average optical reflectance of at least 30%, and the reflective polarizer has an average optical reflectance Rs for a first polarization state, an average optical transmittance Tp for an orthogonal second polarization state, and an average optical reflectance Rp for the second polarization state, where Tp?80%, Rp?1%, and 50%?Rs?95%.

Abstract: An optical assembly includes an integral lens assembly having one or more lenses bonded to each other with spaced apart major first and second lens surfaces. First and second optical films are bonded to respective major first and second lens surfaces. The first and second optical films includes a plurality of polymeric layers. Each of the polymeric layers have an average thickness of less than about 500 nm. For a substantially normally incident light and a visible wavelength range the plurality of polymeric layers in the first optical film has an average optical transmittance and an average optical reflectance of greater than about 70% for a first polarization state and an orthogonal second polarization state, respectively. The plurality of polymeric layers in the second optical film has an average optical transmittance of greater than about 70% for at least one of the first and second polarization states.

Abstract: Optical films are disclosed that include a plurality of interference layers. Each interference layer reflects or transmits light primarily by optical interference. The total number of the interference layers is less than about 1000. For a substantially normally incident light in a predetermined wavelength range, the plurality of interference layers has an average optical transmittance greater than about 85% for a first polarization state, an average optical reflectance greater than about 80% for an orthogonal second polarization state, and an average optical transmittance less than about 0.2% for the second polarization state.

Abstract: A technique of determining the presence of a species in a sample may include passing light through an optical filter. In an example, the optical filter may include a spatially variant microreplicated layer optically coupled to a wavelength selective filter. The wavelength selective filter may have a light incidence angle-dependent optical band. The spatially variant microreplicated layer may be configured to transmit light to a first optical region of the wavelength selective filter at a first predetermined incidence angle and to a second optical region of the wavelength selective filter at a second predetermined incidence angle.

Abstract: A partial reflector including a plurality of optical repeat units where each optical repeat unit includes first and second polymer layers is described. A refractive index difference between the first and second polymer layers along a first axis may be ?ny, a refractive index difference between the first and second polymer layers along an orthogonal second axis may be ?nx, where |?nx| is at least 0.1 and |?ny| is no more than 0.04. The optical repeat units may have a smallest optical thickness T1 proximate a first side of the optical stack and a largest optical thickness T2 proximate an opposite second side of the optical stack, where (T2?T1)/(T2+T1) can be a range of 0.05 to 0.2, and T2 can be at least 350 nm and no more 1250 nm. The partial reflector may be used in a circular polarizer for correcting color shift with view angle in a display.

Abstract: Optical films and polarizing beam splitters including the optical films are described. In some cases, the optical film includes a first optical stack disposed on, and spaced apart by one or more spacer layers from, a second optical stack, each optical stack comprising a plurality of polymeric interference layers reflecting and transmitting light primarily by optical interference in a same predetermined wavelength range. Each optical stack has interference layers closer to the one or more spacer layers that reflect longer wavelengths and interference layers farther from the one or more spacer layers that reflect shorter wavelengths.

Abstract: Optical films and polarizing beam splitters including the optical films are described. In some cases, the optical film includes a first optical stack disposed on, and spaced apart by one or more spacer layers from, a second optical stack, each optical stack comprising a plurality of polymeric interference layers reflecting and transmitting light primarily by optical interference in a same predetermined wavelength range. Each optical stack has interference layers closer to the one or more spacer layers that reflect longer wavelengths and interference layers farther from the one or more spacer layers that reflect shorter wavelengths.

Abstract: A partial reflector including a plurality of optical repeat units where each optical repeat unit includes first and second polymer layers is described. A refractive index difference between the first and second polymer layers along a first axis may be Any, a refractive index difference between the first and second polymer layers along an orthogonal second axis may be ?ƒ?, where |???| is at least 0.1 and |?ny| is no more than 0.04. The optical repeat units may have a smallest optical thickness T1 proximate a first side of the optical stack and a largest optical thickness T2 proximate an opposite second side of the optical stack, where (T2?T1)/(T2+T1) is in a range of 0.05 to 0.2, and T2 is at least 350 nm and no more 1250 nm. The partial reflector may be used in a circular polarizer for correcting color shift with view angle in a display.

Abstract: An article including a reflector with a reflectance band that is substantially constant as a function of an incidence angle; a polymeric multilayer film packet including a front surface partial reflector with a reflectivity that increases with an increasing incidence angle away from the normal; and a wavelength-selective absorber with a transmission band that at least partially coincides with the reflectance band of the reflector.

Abstract: An article including a reflector with a reflectance band that is substantially constant as a function of an incidence angle; a polymeric multilayer film packet including a front surface partial reflector with a reflectivity that increases with an increasing incidence angle away from the normal; and a wavelength-selective absorber with a transmission band that at least partially coincides with the reflectance band of the reflector.

Abstract: A reflective polarizer has substantially distinct blue, green and red-infrared reflection bands for substantially normally incident light. A display system includes a display panel including blue, green and red light emitting pixels having respective blue, green and red peak wavelengths and respective blue, green and red FWHMs; and the reflective polarizer disposed on the light emitting pixels. The reflective polarizer: reflects at least about 60% of the incident light for each of the blue and green peak wavelengths and at least about 40% of the incident light for the red peak wavelength for a first polarization state; transmits at least about 60% of the incident light for each of the blue, green and red peak wavelengths for an orthogonal second polarization state; and has an absorption peak at a wavelength between the green and red FWHMs.

Abstract: A reflective polarizer is such that for substantially normally incident light and for blue, green and red wavelengths, the reflective polarizer: has a transmission spectrum including a blue transmission stop band for the incident light polarized along a first direction; reflects at least about 50% of the incident light polarized along the first direction for the blue wavelength; transmits at least about 50% of the incident light polarized along an orthogonal second direction for each of the blue, green and red wavelengths; and transmits between about 50% and about 95% of the incident light polarized along the first direction for each of the green and red wavelengths. The blue transmission stop band has opposing first and second band edges having respective first and second slope magnitudes S1 and S2, where S1/S2?2. A display system includes the reflective polarizer disposed on a display panel.

Abstract: Multilayer optical film reflective polarizers previously considered to have excessive off-axis color can provide adequate performance in an LC display in an “on-glass” configuration, laminated to a back absorbing polarizer of the display, without any light diffusing layer or air gap in such laminate. The reflective polarizer is a tentered-one-packet (TOP) multilayer film, having only one packet of microlayers, and oriented using a standard tenter such that birefringent microlayers in the film are biaxially birefringent. The thickness profile of optical repeat units (ORUs) in the microlayer packet is tailored to avoid excessive perceived color at normal and oblique angles. Color at high oblique angles in the white state of the display is reduced by positioning thicker ORUs closer to the absorbing polarizer, and by ensuring that, with regard to a boxcar average of the ORU thickness profile, the average slope from an ORU(600) to an ORU(645) does not exceed 1.

Abstract: A display system includes a display panel including a plurality light emitting pixels and a reflective polarizer disposed on the light emitting pixels. The reflective polarizer can have a reflection band having a lower overlap with an emission spectrum of red light emitting pixels for substantially normally incident light and a higher overlap with the emission spectrum of the red light emitting pixels for at least one incident angle greater than about 40 degrees. The reflective polarizer can have a reflection band overlapping an emission spectrum of blue light emitting pixels for substantially normally incident light.

Abstract: A display system is disclosed and includes a display and a reflective polarizer disposed on the display. For substantially normally incident light, for a primary wavelength ?b, the reflective polarizer transmits at least 60% of the incident light having a first polarization state x and reflects at least 60% of the incident light having an orthogonal second polarization state y. For each of a first wavelength ?uv and a second wavelength ?bg, 0<?b-?uv?100 nm#and 0<?bg-?b?100 nm, the reflective polarizer transmits at least 40% of the incident light for each of the first and second polarization states.

Abstract: An optical stack including a first reflective polarizer adhered to a second reflective polarizer is described. For normally incident light and each wavelength in a same predetermined wavelength range, each reflective polarizer transmits at least 80% of light polarized along a pass axis of the reflective polarizer and reflects at least 90% of light polarized along an orthogonal block axis of the reflective polarizer. Each reflective polarizer includes a plurality of polymeric interference layers reflecting and transmitting light primarily by optical interference in the predetermined wavelength range. A separation between the two polymeric interference layers in the plurality of polymeric interference layers farthest from each other are d1 and d2 for the respective first and second reflective polarizers, d1 is at least 20% less than d2. Polarizing beam splitters including the optical stack and optical systems including the polarizing beam splitter are described.

Abstract: Optical films are disclosed that include a plurality of interference layers. Each interference layer reflects or transmits light primarily by optical interference. The total number of the interference layers is less than about 1000. For a substantially normally incident light in a predetermined wavelength range, the plurality of interference layers has an average optical transmittance greater than about 85% for a first polarization state, an average optical reflectance greater than about 80% for an orthogonal second polarization state, and an average optical transmittance less than about 0.2% for the second polarization state.