High efficiency optical devices
First Claim
1. An optical device comprising opposing optical surfaces arranged to form a wedge, at least a portion of the opposing optical surfaces comprising a multilayer optical film that comprises alternating layers of at least two materials, wherein the multilayer optical film reflects light over a wavelength band of interest as a function of thicknesses of the alternating layers, and further wherein at least one of the materials has a stress induced birefringence.
2 Assignments
0 Petitions
Accused Products
Abstract
Optical devices according to the present invention include a multilayer optical film in which at least one of the layers comprises an oriented birefringent polymer. The multilayer optical film exhibits low absorptivity and can reflect light approaching at shallow angles as well as normal to the film.
175 Citations
20 Claims
- 1. An optical device comprising opposing optical surfaces arranged to form a wedge, at least a portion of the opposing optical surfaces comprising a multilayer optical film that comprises alternating layers of at least two materials, wherein the multilayer optical film reflects light over a wavelength band of interest as a function of thicknesses of the alternating layers, and further wherein at least one of the materials has a stress induced birefringence.
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2. An optical device comprising opposing optical surfaces arranged to form a wedge, at least a portion of the opposing optical surfaces comprising a multilayer optical film that comprises alternating layers of at least two materials, and further wherein at least one of the materials has a stress induced birefringence, wherein the multilayer optical film comprises alternating first and second polymeric materials, wherein the absolute value of the difference in index of refraction between the first and second polymeric material is Δ
- nx along a first axis in the plane of the film and is Δ
nz along a second axis orthogonal to the plane of the film, and wherein the ratio Δ
nz/Δ
nx is less than 0.5.
- nx along a first axis in the plane of the film and is Δ
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3. An optical device comprising opposing optical surfaces arranged to form a wedge, at least a portion of the opposing optical surfaces comprising a multilayer optical film that comprises alternating layers of at least two materials, and further wherein at least one of the materials has a stress induced birefringence, wherein the multilayer optical film comprises alternating first and second polymeric materials, wherein the absolute value of the difference in index of refraction between the first and second polymeric material is Δ
- nx along an in-plane direction of the film and is Δ
nz along a thickness direction of the film, end wherein Δ
nx is at least 0.05 and Δ
nz is less than Δ
nx.
- nx along an in-plane direction of the film and is Δ
- 11. An optical device comprising opposing optical surfaces arranged to form a light pipe, at least a portion of the opposing optical surfaces comprising a multilayer optical film that comprises alternating layers of at least two materials, wherein the multilayer optical film reflects light over a wavelength band of interest as a function of thicknesses of the alternating layers, and further wherein at least one of the materials has a stress induced birefringence.
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12. An optical device comprising opposing optical surfaces arranged to form a light pipe, at least a portion of the opposing optical surfaces comprising a multilayer optical film that comprises alternating layers of at least two materials, and further wherein at least one of the materials has a stress induced birefringence, wherein the multilayer optical film comprises alternating first and second polymeric materials, wherein the absolute value of the difference in index of refraction between the first and second polymeric material is Δ
- nx along a first axis in the plane of the film and is Δ
nz along a second axis orthogonal to the plane of the film, and wherein the ratio Δ
nz/Δ
nx is less than 0.5.
- nx along a first axis in the plane of the film and is Δ
-
13. An optical device comprising opposing optical surfaces arranged to form a light pipe, at least a portion of the opposing optical surfaces comprising a multilayer optical film that comprises alternating layers of at least two materials, and further wherein at least one of the materials has a stress induced birefringence, wherein the multilayer optical film comprises alternating first and second polymeric materials, wherein the absolute value of the difference in index of refraction between the first and second polymeric material is Δ
- nx along an in-plane direction of the film and is Δ
nz along a thickness direction of the film, and wherein Δ
nx is at least 0.05 and Δ
nz is less than Δ
nx.
- nx along an in-plane direction of the film and is Δ
Specification