US3698795A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diffraction grating with two diffracting surfaces
Assignee: Ropintassco Holdings LP
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Filing: 1971-01-26
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Granted: 1972-10-17
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Expires: 1991-01-26
Abstract
Abstract A spectral dispersion reflective grating comprises a vacuum deposited metal film with straight, parallel grooves. The film is of a thickness such that it is opaque and both its surfaces are substantially identical. The film is supported on a glassy blank or frame which permits light to be transmitted to, and reflectively diffracted from, either or both of the film surfaces. Elements on the support detachably engage a grating in the mount for use of either grooved film surface or for simultaneous use in a double monochromator. The support elements define a plane parallel to the film plane insuring that in reversible or scanning use both film surfaces will maintain a desired relation in a scanning or reversible spectrometric system. When the two film surfaces are on a single glassy blank or contained between light transmissive glassy blanks of different refractive indices, different blaze wavelengths appear outside the blanks at each side of the grating without changing the spectral dispersion.
Inventors
- 👤 Bruce K Flint
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 11:37
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/18; G02B5/1814
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
119 words
A diffraction grating for spectrometric dispersion of light of predetermined wavelengths in spectral order in a dispersion plane comprising: a thin reflective film of thickness opaque to said predetermined wavelengths and corrugated in cross section so that the same straight, parallel grooves appear at both surFaces, and support means holding said film in planar form, the support allowing transmission of light of said predetermined wavelengths on paths incident to both of said film surfaces, said film being reflectively diffractive of substantially identically dispersed spectra in precise spectral order and highest spectrometric precision from each of the two surfaces of the film, and said support being transmissive of at least one of the identical spectra with unaltered precision of dispersion.
Claim 2
Dependent Claim
119 words
A diffraction grating for spectrometric dispersion of light of predetermined wavelengths in spectral order in a dispersion plane comprising: a thin reflective film of thickness opaque to said predetermined wavelengths and corrugated in cross section so that the same straight, parallel grooves appear at both surFaces, and support means holding said film in planar form, the support allowing transmission of light of said predetermined wavelengths on paths incident to both of said film surfaces, said film being reflectively diffractive of substantially identically dispersed spectra in precise spectral order and highest spectrometric precision from each of the two surfaces of the film, and said support being transmissive of at least one of the identical spectra with unaltered precision of dispersion.
Claim 3
Dependent Claim
23 words
A grating according to claim 1 wherein said support means comprises mounting elements defining a plane parallel to the plane of said film.
Claim 4
Dependent Claim
29 words
A grating according to claim 1 wherein said support means comprises a rigid, optically transparent substrate, the film being bonded to the substrate at one surface of the film.
Claim 5
Dependent Claim
22 words
A grating according to claim 3 further characterized by a second optically transparent substrate bonded to the other surface of the film.
Claim 6
Dependent Claim
25 words
A grating according to claim 4 wherein the substrate provides a medium at said one surface of different refractive index than at the other surface.
Claim 7
Dependent Claim
48 words
A grating according to claim 4 wherein the film grooves are blazed for predominant diffraction of a predetermined wavelength, and the second substrate is of material having a different index of refraction than the first said substrate, thereby to alter the blaze wavelength from said other film surface.
Claim 8
Dependent Claim
25 words
A grating according to claim 3 wherein the substrate provides a medium at said one surface of different refractive index than at the other surface.
Claim 9
Dependent Claim
25 words
A grating according to claim 1 wherein said film is supported only at its edges by a frame exposing both film surfaces to ambient atmosphere.
Claim 10
Dependent Claim
68 words
A grating according to claim 1 in combination with a spectral dispersion system comprising means for directing incident light on one side of a dispersing plane, means for focusing light dispersed from said plane on a dispersion plane, and means mounting said grating with said film in said dispersion plane, said mounting means holding said grating with either surface of said grooved film facing said light directing means.
Claim 11
Dependent Claim
28 words
A grating according to claim 9 wherein said grating comprises mounting elements engaging said mounting means and defining a reference plane coincident with the plane of the film.
Claim 12
Dependent Claim
28 words
A grating according to claim 10 wherein said mounting means comprises means pivotally supporting the mounting means for rotation about an axis in said reference and film planes.
Claim 13
Dependent Claim
17 words
A grating according to claim 11 wherein the grooves of said film are parallel to said axis.
Claim 14
Dependent Claim
19 words
A grating according to claim 9 characterized by second means for directing incident light on the other film surface.
Claim 15
Dependent Claim
56 words
A grating according to claim 13 wherein the film grooves are blazed for predominant diffraction of a predetermined wavelength and said film support means comprises at least one optically transparent substrate on one surface of the film providing a medium at one surface of the film of different refractive index than at the other film surface.
Claim 16
Dependent Claim
47 words
A grating according to claim 1 in combination with a spectral dispersion system comprising means pivotally mounting said grating for rotation on an axis lying in said film plane parallel to the grooves of the film, and means for directing light on both surfaces of the film.
Claim 17
Dependent Claim
28 words
A grating according to claim 15 wherein said grating comprises mounting elements engaging said mounting means and defining a reference plane coincident with the plane of the film.
Claim 18
Dependent Claim
68 words
A grating according to claim 15 wherein the film grooves are blazed for predominant diffraction of a predetermined wavelength and said film support means comprises at least one optically transparent substrate on one surface of the film providing a medium at one surface of the film of different refractive index than at the other film surface thereby to alter the effective blaze wavelength from said other film surface.
Claim 19
Dependent Claim
31 words
A grating according to claim 1 In combination with a mount pivoting the grating on an axis lying in the plane of the film parallel to the grooves of the film.
Claim 20
Dependent Claim
32 words
A grating according to claim 1 wherein said support means comprises a glassy substrate supporting the film on one surface and having a second surface parallel to the first within 3 wavelengths.
Claim 21
Dependent Claim
16 words
A grating according to claim 19 wherein said second surface is optically flat within 2 wavelengths.
Claim 22
Dependent Claim
146 words
A diffraction grating for spectrometric dispersion of predetermined wavelengths of light in a dispersion plance comprising: a thin reflective metallic film of thickness effectively opaque to said predetermined light wavelengths with corrugations forming substantially identical grooves on both surfaces of the film, both said grooved surfaces having the characteristic of diffracting substantially identically dispersed spectra in a dispersion plane and being identically blazed for predominant diffraction of a predetermined wavelength, one of said grooved surfaces being exposed to ambient atmosphere for non-refractive diffraction therefrom, and a glassy support bonded to the other surface of the film, the support being transmissive of said light wavelengths to said one surface and being of sufficient optical quality to allow useful diffraction of spectra with highest spectrometric precision from the back side of the film, thereby altering the blaze wavelength from said other film surface without altering the spectral dispersion.
Claim 23
Dependent Claim
146 words
A diffraction grating for spectrometric dispersion of predetermined wavelengths of light in a dispersion plance comprising: a thin reflective metallic film of thickness effectively opaque to said predetermined light wavelengths with corrugations forming substantially identical grooves on both surfaces of the film, both said grooved surfaces having the characteristic of diffracting substantially identically dispersed spectra in a dispersion plane and being identically blazed for predominant diffraction of a predetermined wavelength, one of said grooved surfaces being exposed to ambient atmosphere for non-refractive diffraction therefrom, and a glassy support bonded to the other surface of the film, the support being transmissive of said light wavelengths to said one surface and being of sufficient optical quality to allow useful diffraction of spectra with highest spectrometric precision from the back side of the film, thereby altering the blaze wavelength from said other film surface without altering the spectral dispersion.
Claim 24
Dependent Claim
101 words
A diffraction grating for spectrometric dispersion of predetermined wavelengths of light in a dispersion plane comprising: a thin reflective metallic film of thickness effectively opaque to said predetermined light wavelengths with corrugations forming substantially identical grooves on both surfaces of the film, both said grooved surfaces having the characteristic of diffracting substantially identical spectra in a dispersion plane, and glassy supports bonded to respective surfaces of the film, each support being transmissive of said light wavelengths to its respective grooved surface, and being of sufficient optical quality to allow useful diffraction of spectra with highest spectrometric precision from each grooved surface.
Claim 25
Dependent Claim
101 words
A diffraction grating for spectrometric dispersion of predetermined wavelengths of light in a dispersion plane comprising: a thin reflective metallic film of thickness effectively opaque to said predetermined light wavelengths with corrugations forming substantially identical grooves on both surfaces of the film, both said grooved surfaces having the characteristic of diffracting substantially identical spectra in a dispersion plane, and glassy supports bonded to respective surfaces of the film, each support being transmissive of said light wavelengths to its respective grooved surface, and being of sufficient optical quality to allow useful diffraction of spectra with highest spectrometric precision from each grooved surface.
Claim 26
Dependent Claim
93 words
A diffraction grating for spectrometric dispersion of predetermined wavelengths of light in dispersion plane comprising: a dispersion plane, and a thin reflective metallic film of thickness effectively opaque to said predetermined light wavelengths with corrugations forming substantially identical grooves on both surfaces of the film, both said grooved surfaces having the characteristic of diffracting substantially identical spectra with highest spectrometric precision in a dispersion plane, and support means attached to at least one of said grooved surfaces at the margin thereof leaving a major area of both said surfaces exposed to ambient atmosphere.
Claim 27
Dependent Claim
93 words
A diffraction grating for spectrometric dispersion of predetermined wavelengths of light in dispersion plane comprising: a dispersion plane, and a thin reflective metallic film of thickness effectively opaque to said predetermined light wavelengths with corrugations forming substantially identical grooves on both surfaces of the film, both said grooved surfaces having the characteristic of diffracting substantially identical spectra with highest spectrometric precision in a dispersion plane, and support means attached to at least one of said grooved surfaces at the margin thereof leaving a major area of both said surfaces exposed to ambient atmosphere.
Claim 28
Dependent Claim
116 words
For diffraction of predetermined wavelengths in a spectral dispersion instrument a new article of commerce comprising a reflection grating including a thin reflective film of thickness opaque to said predetermined wavelengths and corrugated in cross section so that the same straight, parallel grooves appear at both surfaces of the film, and a glassy substrate attached to one surface of and supporting said film, said substrate being optically polished, flat and clear with plane-parallel surfaces, said grating being diffractive from both sides of said film with highest spectrometric precision and being specially adapted for transmission of said light traveling through said substrate to said film for reflective dispersion of light spectra from said film through said substrate.
Claim 29
Dependent Claim
116 words
For diffraction of predetermined wavelengths in a spectral dispersion instrument a new article of commerce comprising a reflection grating including a thin reflective film of thickness opaque to said predetermined wavelengths and corrugated in cross section so that the same straight, parallel grooves appear at both surfaces of the film, and a glassy substrate attached to one surface of and supporting said film, said substrate being optically polished, flat and clear with plane-parallel surfaces, said grating being diffractive from both sides of said film with highest spectrometric precision and being specially adapted for transmission of said light traveling through said substrate to said film for reflective dispersion of light spectra from said film through said substrate.
Claim 30
Dependent Claim
97 words
An optical instrument for precision spectral dispersion of predetermined wavelengths of light comprising: a grating including a thin reflective film of thickness opaque to said predetermined wavelengths and corrugated in cross section so that the same straight, parallel grooves appear at both surfaces of the film, and a glassy substrate attached to one surface of and supporting said film, said substrate being optically polished, flat and clear with plane-parallel surfaces, and means for directing light on one surface of film through said substrate, said grating being diffractive from both sides of said film with highest spectrometric precision.
Claim 31
Dependent Claim
97 words
An optical instrument for precision spectral dispersion of predetermined wavelengths of light comprising: a grating including a thin reflective film of thickness opaque to said predetermined wavelengths and corrugated in cross section so that the same straight, parallel grooves appear at both surfaces of the film, and a glassy substrate attached to one surface of and supporting said film, said substrate being optically polished, flat and clear with plane-parallel surfaces, and means for directing light on one surface of film through said substrate, said grating being diffractive from both sides of said film with highest spectrometric precision.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |