US5812233A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polarization sensitive devices and methods of manufacture thereof
Assignee: Sharp Corp
•
Filing: 1995-09-07
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Granted: 1998-09-22
•
Expires: 2015-09-07
Abstract
Abstract A film of photosensitive material is illuminated from first and second sides with coherent polarized light so as to form an interference pattern within the film. Regions of cyclicly varying refractive index are provided in the film in accordance with the intensity of the interference patten, thereby forming an polarization sensitive refractive index grating. The refractive index grating may be used as a polarization and wavelength dependent mirror, patterned polarizer, beamsplitter or filter.
Inventors
- 👤 Kathryn Walsh
- 👤 Gillian Margaret Davis
- 👤 Paul May
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:29
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/30; G02B5/3083; G02B27/00; G02B27/28; G02B27/283; G02B27/288
Claims Analysis
Total Claims: 38
Claim 1
Independent Claim
49 words
A polarization sensitive device comprising a liquid crystal material having a first surface, the material having been written so as to define a first repeating pattern of refractive index variation to light of a first polarization, the repeating pattern extending along a direction substantially perpendicular to the first surface.
Claim 2
Dependent Claim
49 words
A polarization sensitive device comprising a liquid crystal material having a first surface, the material having been written so as to define a first repeating pattern of refractive index variation to light of a first polarization, the repeating pattern extending along a direction substantially perpendicular to the first surface.
Claim 3
Dependent Claim
29 words
A device as claimed in claim 1, wherein the material comprises a liquid crystal monomer material, the material having been written to at least partially polymerize the monomer material.
Claim 4
Dependent Claim
32 words
A device as claimed in claim 1, wherein the material comprises a liquid crystal polymer material, the material having been written to at least partially cross-link the polymer chains of the material.
Claim 5
Dependent Claim
14 words
A device as claimed in claim 1, wherein the material comprises a birefringent material.
Claim 6
Dependent Claim
14 words
A device as claimed in claim 4, wherein the birefringent material exhibits photoinduced birefringence.
Claim 7
Dependent Claim
14 words
A device as claimed in claim 5, in which the material is a photopolymer.
Claim 8
Dependent Claim
14 words
A device as claimed in claim 1, in which the material is a film.
Claim 9
Dependent Claim
52 words
A polarization sensitive device as claimed in claim 1, wherein unpolarized light which is incident on the material is resolved into a first and second orthogonal circularly polarized components and wherein the first circularly polarized component is transmitted through the material and the second circularly polarized component is reflected by the material.
Claim 10
Dependent Claim
23 words
A polarization sensitive device as claimed in claim 1, in which the refractive index of the material is a cyclicly varying continuous function.
Claim 11
Dependent Claim
32 words
A polarization sensitive device as claimed in claim 1, wherein the material comprises a liquid crystal material and the refractive index of the material to light is a cyclicly varying discontinuous function.
Claim 12
Dependent Claim
31 words
A polarization sensitive device as claimed in claim 8, in which the refractive index to light of the second polarization is substantially invariant with respect to displacement from the first surface.
Claim 13
Dependent Claim
17 words
A device as claimed in claim 1, wherein the first repeating pattern is a continuously varying pattern.
Claim 14
Dependent Claim
25 words
A device as claimed in claim 1, in which the device is patterned so as to define a plurality of regions having refractive index variations.
Claim 15
Dependent Claim
16 words
A device as claimed in claim 1, in which the material is formed on a substrate.
Claim 16
Dependent Claim
14 words
A device as claimed in claim 14, in which the substrate is fused silica.
Claim 17
Dependent Claim
45 words
A device as claimed in claim 1, in which the device has at least one further repeating pattern of refractive index variation to light of the first, second, or a further polarization, the at least one further pattern being substantially parallel to the first pattern.
Claim 18
Dependent Claim
20 words
A device as claimed in claim 16, wherein the at least one further pattern is superimposed upon the first pattern.
Claim 19
Dependent Claim
21 words
A device as claimed in claim 16, wherein the at least one further pattern is spatially separated from the first pattern.
Claim 20
Dependent Claim
20 words
A device as claimed in claim 1, wherein the pattern is written into the material using an optical writing technique.
Claim 21
Dependent Claim
20 words
A device as claimed in claim 19, wherein the optical writing technique involves a step of irradiation by ultra-violet light.
Claim 22
Dependent Claim
14 words
A polarization sensitive beamsplitter comprising a polarization sensitive device as claimed in claim 1.
Claim 23
Dependent Claim
14 words
A polarization sensitive reflector comprising a polarization sensitive device as claimed in claim 1.
Claim 24
Independent Claim
73 words
A method for forming a polarization sensitive device, comprising the steps of optically writing a liquid crystal material having a first surface so as to define a first repeating pattern of refractive index variation to light of a first polarization, the repeating pattern extending along a direction substantially perpendicular to the first surface, fixing the pattern in the liquid crystal material, and a subsequent fixing step for fixing the remaining liquid crystal material.
Claim 25
Independent Claim
73 words
A method for forming a polarization sensitive device, comprising the steps of optically writing a liquid crystal material having a first surface so as to define a first repeating pattern of refractive index variation to light of a first polarization, the repeating pattern extending along a direction substantially perpendicular to the first surface, fixing the pattern in the liquid crystal material, and a subsequent fixing step for fixing the remaining liquid crystal material.
Claim 26
Dependent Claim
26 words
A method as claimed in claim 23, wherein the step of optically writing comprises irradiating the liquid crystal material with ultra-violet light of spatially varying intensity.
Claim 27
Dependent Claim
31 words
A method as claimed in claim 24, wherein the irradiation is achieved using at least two ultra-violet light beams arranged to interfere with one another to produce the spatially varying intensity.
Claim 28
Dependent Claim
49 words
A method as claimed in any one of claim 23, wherein the subsequent fixing step comprises a step of reorienting the alignment of any part of the liquid crystal which is not already fixed, and a step of irradiating the liquid crystal material with light of substantially uniform intensity.
Claim 29
Dependent Claim
24 words
A method as claimed in claim 26, wherein the step of reorienting the liquid crystal material comprises heating the material to the isotropic phase.
Claim 30
Dependent Claim
26 words
A method as claimed in claim 26, wherein the step of reorienting the liquid crystal material comprises applying an electric field across the liquid crystal material.
Claim 31
Dependent Claim
19 words
A method as claimed in claim 23, wherein the liquid crystal material comprises a photo-polymerizable liquid crystal monomer material.
Claim 32
Dependent Claim
19 words
A method as claimed in claim 23, wherein the liquid crystal material comprises a photo-cross-linkable liquid crystal polymer material.
Claim 33
Dependent Claim
28 words
A method as claimed in claim 23, in which at least one region of the device is multiply exposed so as to form a plurality of patterns therein.
Claim 34
Independent Claim
81 words
A method of forming a polarization sensitive device, comprising illuminating first and second substantially parallel surfaces of a photosensitive material exhibiting photo-induced birefringence with first and second polarized coherent radiations, respectively, so as to define a first pattern of spatial variation in refractive index in the photosensitive material in accordance with an interference pattern between the first and second radiations, wherein the photosensitive material is subsequently deformed so as to change the spatial periodicity of the pattern of refractive index variation.
Claim 35
Independent Claim
81 words
A method of forming a polarization sensitive device, comprising illuminating first and second substantially parallel surfaces of a photosensitive material exhibiting photo-induced birefringence with first and second polarized coherent radiations, respectively, so as to define a first pattern of spatial variation in refractive index in the photosensitive material in accordance with an interference pattern between the first and second radiations, wherein the photosensitive material is subsequently deformed so as to change the spatial periodicity of the pattern of refractive index variation.
Claim 36
Dependent Claim
29 words
A method as claimed in claim 32, in which selected regions of the photosensitive material are illuminated with the first and second radiations so as to pattern the device.
Claim 37
Dependent Claim
43 words
A method as claimed in claim 32, in which the angle of incidence between the first and second surfaces and the first and second radiations, respectively, is selected so as to define the first pattern of spatial variation with a predetermined spatial periodicity.
Claim 38
Dependent Claim
15 words
A method as claimed in claim 32, in which the polarized coherent radiations are light.
References Cited (Backward Citations)
US3610729A
Cited
US3622220A
Cited
US4412719A
Cited
US4983479A
Cited
US4993789A
Cited
US5189532A
Cited
EP0404098A2
Cited
US5161039A
Cited
US5105298A
Cited
US5153670A
Cited
US5198912A
Cited
WO1992009915A1
Cited
US5621547A
Cited
US5243449A
Cited
JPH05181401A
Cited
JPH04360103A
Cited
EP0547949A1
Cited
US5410421A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2001-09-21 | 2002-03-23 | 2002-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-09-21 | 2006-03-23 | 2006-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-09-21 | 2010-03-23 | 2010-09-22 | $7700.00 | Window Closed / Lapsed |