Multilayer optical film with output confinement in both polar and azimuthal directions and related constructions
First Claim
1. A reflective film having substantially flat outer surfaces, comprising:
- a plurality of microlayers arranged into optical repeat units for reflecting light over an extended wavelength band, adjacent microlayers exhibiting substantial in-plane refractive index mismatches Δ
nx along an x-axis and Δ
ny along a y-axis, such that for normally incident light in the extended wavelength band, the film has a reflectivity Rnormalx for such light polarized along the x-axis and a reflectivity Rnormaly for such light polarized along the y-axis, Rnormalx and Rnormaly both being at least 75%;
wherein adjacent microlayers also exhibit a substantial refractive index mismatch Δ
nz along an out-of-plane z-axis, such that for light in the extended wavelength band incident on the film in a first plane of incidence, the film has a reflectivity R1 of no more than half of Rnormalmin for such light that is p-polarized and incident at an angle θ
oblique, where Rnormalmin is the lesser of Rnormalx and Rnormaly; and
wherein Δ
nx and Δ
ny are different enough so that for light in the extended wavelength band incident on the film in a second plane of incidence orthogonal to the first plane, the film has a reflectivity R2 of at least 75% for such light that is p-polarized, for all angles of incidence.
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Accused Products
Abstract
A film includes microlayers arranged into optical repeat units. Adjacent microlayers have in-plane refractive index mismatches Δnx, Δny tailored to provide mirror-like on-axis properties, such that the film has a reflectivity for normally incident light in an extended wavelength band of at least 75% for any polarization. Adjacent microlayers also have a refractive index mismatch Δnz that provides the film with reduced reflectivity R1 and increased transmission for p-polarized light in the extended wavelength band incident on the film in a first plane of incidence at an angle θoblique, where R1 is no more than half of the minimum of on-axis reflectivity. Further, Δnx and Δny are different enough so that for light incident on the film in a second plane of incidence orthogonal to the first plane, the film has a reflectivity R2 of at least 75% for such light that is p-polarized and incident at any angle.
60 Citations
21 Claims
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1. A reflective film having substantially flat outer surfaces, comprising:
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a plurality of microlayers arranged into optical repeat units for reflecting light over an extended wavelength band, adjacent microlayers exhibiting substantial in-plane refractive index mismatches Δ
nx along an x-axis and Δ
ny along a y-axis, such that for normally incident light in the extended wavelength band, the film has a reflectivity Rnormalx for such light polarized along the x-axis and a reflectivity Rnormaly for such light polarized along the y-axis, Rnormalx and Rnormaly both being at least 75%;wherein adjacent microlayers also exhibit a substantial refractive index mismatch Δ
nz along an out-of-plane z-axis, such that for light in the extended wavelength band incident on the film in a first plane of incidence, the film has a reflectivity R1 of no more than half of Rnormalmin for such light that is p-polarized and incident at an angle θ
oblique, where Rnormalmin is the lesser of Rnormalx and Rnormaly; andwherein Δ
nx and Δ
ny are different enough so that for light in the extended wavelength band incident on the film in a second plane of incidence orthogonal to the first plane, the film has a reflectivity R2 of at least 75% for such light that is p-polarized, for all angles of incidence. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification