US3893749A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the determination of an assembly having isotropic oblique reflection in an extensive spectral region and assemblies obtained by this process
Assignee: Societe dOptique Precision Electronique et Mecanique SOPELEM SA
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Filing: 1973-10-24
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Granted: 1975-07-08
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Expires: 1993-10-24
Abstract
Abstract A reflecting assembly for polarized white light includes at least one mirror associated with a birefringent compensator preventing the reflected light from having a large phase anisotropy. The mirror or mirrors are metallic and covered with a protective silica layer having a geometric thickness of from 0 to about 400A. The birefringent compensator is a crystalline plate of predetermined thickness depending upon the thickness of the protective layer. Known compensators may be used in place of the birefringent plate.
Inventors
- 👤 Michael Ferray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:34
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/30; G02B5/3083; G02B5/08
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
113 words
Optical assembly for the oblique reflection of a beam of polarized light covering a wide spectrum of wave lengths comprising a plane metallic mirror, a protective layer of transparent dielectric on said mirror having an optical thickness of between 0 and 600A, the beam of light impinging on and being reflected by the mirror and protective layer and crystalline birefringent compensating means receiving the reflected light having birefringent compensation equivalent to that of a crystalline plate having a thickness for which the anisotropy of phases created by said means compensates exactly for the anisotrophy of phases created by said mirror for the means wave length of the spectrum of the beam of light.
Claim 2
Dependent Claim
113 words
Optical assembly for the oblique reflection of a beam of polarized light covering a wide spectrum of wave lengths comprising a plane metallic mirror, a protective layer of transparent dielectric on said mirror having an optical thickness of between 0 and 600A, the beam of light impinging on and being reflected by the mirror and protective layer and crystalline birefringent compensating means receiving the reflected light having birefringent compensation equivalent to that of a crystalline plate having a thickness for which the anisotropy of phases created by said means compensates exactly for the anisotrophy of phases created by said mirror for the means wave length of the spectrum of the beam of light.
Claim 3
Dependent Claim
175 words
Method of compensating for the anisotrophy of phases created by the reflection of a polarized beam of light covering a wide spectrum of wave lengths by a plane metallic mirror protected by a layer of transparent dielectric having a thickness of 0 to 600A, the steps of directing the reflected beam of light through a birefringent compensating crystalline plate, adjusting the thickness of the plate whereby the anisotrophy of phases created by the plate compensates for the anisotrophy of phases created by the mirror for the mean wave length of the spectrum of the beam of light, determining the adjusted thickness of the plate by measuring the anisotrophy of phases created by the mirror as a function of wave length, preparing a set of curves of the variation of the anisotrophy of phases of the birefringent plate as a function of the wave length and for a series of thicknesses for the plate and then finding the thickness of the plate from the curve providing exact compensation for the mean wave length of the spectrum.
Claim 4
Dependent Claim
175 words
Method of compensating for the anisotrophy of phases created by the reflection of a polarized beam of light covering a wide spectrum of wave lengths by a plane metallic mirror protected by a layer of transparent dielectric having a thickness of 0 to 600A, the steps of directing the reflected beam of light through a birefringent compensating crystalline plate, adjusting the thickness of the plate whereby the anisotrophy of phases created by the plate compensates for the anisotrophy of phases created by the mirror for the mean wave length of the spectrum of the beam of light, determining the adjusted thickness of the plate by measuring the anisotrophy of phases created by the mirror as a function of wave length, preparing a set of curves of the variation of the anisotrophy of phases of the birefringent plate as a function of the wave length and for a series of thicknesses for the plate and then finding the thickness of the plate from the curve providing exact compensation for the mean wave length of the spectrum.
Claim 5
Dependent Claim
182 words
Method of compensating for the anisotrophy of phases created by the reflection of a polarized beam of light covering a wide spectrum of wave lengths by a plane metallic mirror protected by a layer of transparent dielectric having a thickness of 0 to 600A, the steps of directing the reflected beam of light through a birefringent compensating crystalline plate, adjusting the thickness of the protective layer as a function of the thickness of the plate whereby the anisotrophy of phases created by the mirror compensates for anisotrophy of phases created by the plate for the mean wave length of the spectrum of the beam light, determining the adjusted thickness of the layer by measuring the variation of the anisotrophy of phases of the plate as a function of wave length, preparing a set of curves of the variation of anisotrophy of phases for the mirror as a functIon of wave length and for a series of thicknesses of the layer and then finding the thickness of the layer from the curve providing exact compensation for the mean wave length of the spectrum.
Claim 6
Dependent Claim
182 words
Method of compensating for the anisotrophy of phases created by the reflection of a polarized beam of light covering a wide spectrum of wave lengths by a plane metallic mirror protected by a layer of transparent dielectric having a thickness of 0 to 600A, the steps of directing the reflected beam of light through a birefringent compensating crystalline plate, adjusting the thickness of the protective layer as a function of the thickness of the plate whereby the anisotrophy of phases created by the mirror compensates for anisotrophy of phases created by the plate for the mean wave length of the spectrum of the beam light, determining the adjusted thickness of the layer by measuring the variation of the anisotrophy of phases of the plate as a function of wave length, preparing a set of curves of the variation of anisotrophy of phases for the mirror as a functIon of wave length and for a series of thicknesses of the layer and then finding the thickness of the layer from the curve providing exact compensation for the mean wave length of the spectrum.
Claim 7
Dependent Claim
40 words
An optical assembly as described in claim 1 for reflection at an angle of incidence of 45* of white polarized light, the mirror being bare aluminum and the plate being a quartz plate having a thickness of 2.2 Mu .
Claim 8
Dependent Claim
36 words
An optical assembly as described in claim 4, for the reflection at an angle of incidence of 45* of white polarized light, the mirror being bare aluminum and the birefringent compensating means being a birefringent compensator.
Claim 9
Dependent Claim
42 words
An optical assembly as described in claim 1 for the reflection at an angle of incidence of 45* of polarized white light, the mirror being bare aluminum and the plate being a magnesium fluoride plate having a thickness of 1.7 Mu .
Claim 10
Dependent Claim
35 words
An optical assembly as described in claim 1 for the reflection at an angle of incidence 45* of white polarized light, the mirror being bare aluminum and the birefringent compensating means being a birefringent compensator.
References Cited (Backward Citations)
US2464141A
Cited
US3774986A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-07 | 1979-01-06 | 1979-07-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-07 | 1983-01-06 | 1983-07-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-07 | 1987-01-06 | 1987-07-08 | $7700.00 | Window Closed / Lapsed |