Patent EP0442206A2 successfully refreshed from Google Patents.
EP0442206A2
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Holographic filter
Assignee: Physical Optics Corp
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Filing: 1990-12-12
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Granted: —
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Expires: 2010-12-12
Abstract
Abstract A holographic filter comprises a volume hologram (36) recorded with Bragg surfaces (38) for use in spectroscopic and spectral splitting applications. The Bragg planes (38) in the holographic filter can be recorded to satisfy virtually any design constraint imposed upon the filter such as Raman, Lippmann, non-Snellian (slanted), curved, and multiplexed spectral filters. The holographic filter achieves maximal reduction of secondary maxima and sidelobes and obtains large wavelength selectivities, and varied grating constants.
Inventors
- 👤 Tomasz P. Jannson
- 👤 Joanna L. Jannson
- 👤 Michael T. Feeney
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 14:24
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/32; G01; G01J; G01J3/00; G01J3/12; G01J3/18; G01J3/1838
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
9 words
A holographic Lippmann Bragg filter in a spectroscopic system.
Claim 2
Dependent Claim
15 words
The invention as defined in claim 1, wherein the filter is a holographic Raman filter.
Claim 3
Dependent Claim
16 words
A holographic Lippmann Bragg filter which rejects an incident quasi-monochromatic collimated beam in a spectroscopic system.
Claim 4
Dependent Claim
14 words
The invention as defined in claim 3, wherein the beam is a laser beam.
Claim 5
Dependent Claim
14 words
A holographic Lippmann Bragg filter which filters light incident upon a wavelength measuring meter.
Claim 6
Dependent Claim
13 words
The invention as defined in claim 5 wherein the meter is a spectrophotometer.
Claim 7
Dependent Claim
39 words
A holographic Lippmann Bragg filter which protects light wave measuring devices from incident laser beam light having wavelength λ₀ but which allows passage of light having wavelengths other than λ₀ to increase system accuracy and signal to noise ratios.
Claim 8
Dependent Claim
10 words
A filter in a spectroscopic system comprising a Bragg hologram.
Claim 9
Dependent Claim
16 words
The invention as defined in claim 8 wherein the Bragg planes in the hologram are slanted.
Claim 10
Dependent Claim
16 words
The invention as defined in claim 8 wherein the Bragg planes in the hologram are curved.
Claim 11
Dependent Claim
24 words
The invention as defined in claim 8 wherein the Bragg planes in the hologram are curved to focus unwanted light to a particular point.
Claim 12
Dependent Claim
19 words
The invention as defined in claim 8, wherein the hologram has a grating constant which varies throughout the hologram.
Claim 13
Dependent Claim
22 words
The invention as defined in claim 8, wherein the amplitude of the index of refraction of the hologram varies throughout the hologram.
Claim 14
Dependent Claim
19 words
The invention as defined in claim 8, wherein the refractive index profile of the hologram varies throughout the hologram.
Claim 15
Dependent Claim
13 words
The invention as defined in claim 8, wherein a hologram is slightly absorptive.
Claim 16
Dependent Claim
24 words
The invention as defined in claim 8, wherein the grating constant changes with respect to the axis perpendicular to the surface of the hologram.
Claim 17
Dependent Claim
15 words
The invention as defined in claim 8 the refractive index profile of which is quasi-rectangular.
Claim 18
Dependent Claim
15 words
The invention as defined in claim 8 the refractive index profile of which is sinusoidal.
Claim 19
Dependent Claim
16 words
The invention as defined in claim 8 the refractive index of which varies throughout the hologram.
Claim 20
Dependent Claim
18 words
The invention as defined in claim 8 the refractive index profile of which has varying bias and amplitude.
Claim 21
Dependent Claim
45 words
In a system in which a laser beam of wavelength λ₀ is incident upon a scattering medium which scatters the laser beam into light waves having a number of wavelengths, a Lippmann Bragg hologram which rejects light waves having wavelengths in the vicinity of λ₀.
Claim 22
Dependent Claim
13 words
A filter in a spectroscopic system comprising a holographic Fabry-Perot etalon transmission filter.
Claim 23
Dependent Claim
18 words
A nonuniform Lippmann Bragg filter the secondary maxima of which are suppressed by the nonuniformities and material absorption.
Claim 24
Dependent Claim
52 words
In a system having a laser beam light source incident upon a scattering medium, and a spectrophotometer to measure wavelengths of light scattered from the scattering medium in order to determine the chemical composition of the scattering medium, a filter which blocks the wavelength of light generated by the laser light source.
Claim 25
Dependent Claim
28 words
A filter in a spectroscopic system comprising multiplexed sets of Bragg holograms each hologram having a distinct grating constants either in sandwiched form or in the same volume.
Claim 26
Dependent Claim
9 words
A curved holographic Bragg filter in a spectroscopic system.
Claim 27
Dependent Claim
5 words
A holographic spectroscopic Raman filter.
Claim 28
Dependent Claim
21 words
An HOE Bragg filter in a spectroscopic system which performs one of the following wavefront operations: filtering, focusing, imaging, or diverging.
Claim 29
Dependent Claim
7 words
An HOE filter in a spectroscopic system.
Claim 30
Dependent Claim
10 words
A holographic Bragg filter with more than 50 Bragg planes.
Claim 31
Dependent Claim
37 words
A holographic Lippmann-Bragg filter having grating constant vertical nonuniformity which splits polychromatic light into two or more parts so that one or more spectral bands are rejected and the transmitted spectrum is smooth with reduced secondary maxima.
Claim 32
Dependent Claim
36 words
A holographic Lippmann-Bragg filter having grating constant vertical nonuniformity which splits polychromatic light into two or more parts so that one or more spectral bands are rejected and the transmitted spectrum is smooth with reduced sidelobes.
References Cited (Backward Citations)
No citation records indexed.
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