Patent US3690159A successfully refreshed from Google Patents.
US3690159A
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Holographic interferometry employing image plane holograms
Assignee: Gc Optronics Inc
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Filing: 1970-04-29
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Granted: 1972-09-12
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Expires: 1990-04-29
Abstract
Abstract A hologram of a test specimen is formed in an optical arrangement including a lens which focuses coherent light reflected by the object onto a photographic plate. A real-time interferometric analysis of the deformation of the object as a result of loading is made using the resulting image-plane hologram. The interference fringe frequency in particular area resulting from gross deformation of the object is decreased to allow the detection of fringe anomalies in that area by suitable translations of the hologram relative to the reconstruction beam. In an alternate embodiment, a pair of image-plane holograms of the object at two states of loading are formed on the same photographic plate by a double-exposure technique using reference beams which bear different angles to the photographic plates during the two exposures. To reconstruct the holograms a pair of reconstruction beams are employed and motion of the beams relative to one another allows the fringe frequency on various areas of the object to be modified.
Inventors
- 👤 Leonard A Kersch
- 👤 Edwin B Champagne
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:29
CPC Classifications
G; G01; G01B; G01B9/00; G01B9/02; G01B9/021; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
108 words
The method of performing holographic interferometric analysis of the deformation of an object, comprising: forming an imageplane hologram of the object at a first time; deforming the object; reconstructing a first wavefront from said hologram using a first source of coherent light; superimposing a second wavefront originating from the object at a second time, after the deformation, on said first wavefront using a source of coherent light which is coherent with said first source; and altering the phase of the reconstructed wavefront relative to the second wavefront so as to modify the interference fringe density on the superimposed image, by moving the first source relative to the hologram.
Claim 2
Independent Claim
108 words
The method of performing holographic interferometric analysis of the deformation of an object, comprising: forming an imageplane hologram of the object at a first time; deforming the object; reconstructing a first wavefront from said hologram using a first source of coherent light; superimposing a second wavefront originating from the object at a second time, after the deformation, on said first wavefront using a source of coherent light which is coherent with said first source; and altering the phase of the reconstructed wavefront relative to the second wavefront so as to modify the interference fringe density on the superimposed image, by moving the first source relative to the hologram.
Claim 3
Dependent Claim
20 words
The method of claim 1 wherein said second wavefront is formed in real time by light reflected from said object.
Claim 4
Independent Claim
101 words
The method of performing holographic interferometric analysis of the deformation of an object, comprising: forming a pair of coincident image-plane holograms of the object at respective first and second times on a record media; deforming the object between said first and second times; reconstructing two wavefronts of the object from said hologram media using first and second reference beams; and altering the phase of one reconstructed wavefront relative to the second reconstructed wavefront so as to modify the interference fringe density on the resultant superimposed image by varying the angle of one of said reconstructing beams relative to the record media.
Claim 5
Independent Claim
101 words
The method of performing holographic interferometric analysis of the deformation of an object, comprising: forming a pair of coincident image-plane holograms of the object at respective first and second times on a record media; deforming the object between said first and second times; reconstructing two wavefronts of the object from said hologram media using first and second reference beams; and altering the phase of one reconstructed wavefront relative to the second reconstructed wavefront so as to modify the interference fringe density on the resultant superimposed image by varying the angle of one of said reconstructing beams relative to the record media.
Claim 6
Dependent Claim
37 words
The method of claim 3 wherein the process of formation of the image-plane hologram employs a reference beam and the angle between the reference beam and the photographic media differs in the formation of the two holograms.
Claim 7
Independent Claim
137 words
The method of performing holographic interferometric analysis, comprising: illuminating an object from a first coherent light source; forming a focused image of light reflected from said object on a photographic media; simultaneously illuminating said media with light coherent with said first light source so as to record an interference pattern between such coherent light and said image, on said media; developing said meDia to form a hologram; reconstructing a wavefront from said hologram employing coherent light from a source; deforming said object; superimposing on the wavefront reconstructed from said hologram a second wavefront consisting of light coherent with the reconstructing light source reflected from said object after said deformation; and modifying the angle of incidence of one of the reconstructing and second wavefront sources to adjust the phase of the reconstructed wavefront relative to the second wavefront.
Claim 8
Independent Claim
137 words
The method of performing holographic interferometric analysis, comprising: illuminating an object from a first coherent light source; forming a focused image of light reflected from said object on a photographic media; simultaneously illuminating said media with light coherent with said first light source so as to record an interference pattern between such coherent light and said image, on said media; developing said meDia to form a hologram; reconstructing a wavefront from said hologram employing coherent light from a source; deforming said object; superimposing on the wavefront reconstructed from said hologram a second wavefront consisting of light coherent with the reconstructing light source reflected from said object after said deformation; and modifying the angle of incidence of one of the reconstructing and second wavefront sources to adjust the phase of the reconstructed wavefront relative to the second wavefront.
Claim 9
Dependent Claim
30 words
The method of claim 5 wherein said second wavefront is generated by illuminating the object with the same light source which is used to reconstruct the wavefront from the hologram.
Claim 10
Independent Claim
189 words
The method of performing holographic interferometric analysis, comprising: illuminating an object from a first coherent light source; forming a focused image of light reflected from said object on a photographic media; simultaneously illuminating said media with light coherent with said first light source so as to record an interference pattern between such coherent light and said image on said media; deforming said object; illuminating the object at a second time with a second light source coherent with said first light source; forming a second focused image of light reflected from said object on said photographic media superimposed on said first focused image; simultaneously illuminating said media with coherent light from said second source to record an interference pattern between such coherent light and said image on said media; developing said media to form a double exposure hologram; illuminating said hologram so as to reconstruct said first and second superimposed wavefronts; and modifying the manner of illumination of said hologram to adjust the phase of the first reconstructed wavefront relative to the second reconstructed wavefront by varying the angle of one of said reconstructing wavefronts relative to the photographic media.
Claim 11
Independent Claim
189 words
The method of performing holographic interferometric analysis, comprising: illuminating an object from a first coherent light source; forming a focused image of light reflected from said object on a photographic media; simultaneously illuminating said media with light coherent with said first light source so as to record an interference pattern between such coherent light and said image on said media; deforming said object; illuminating the object at a second time with a second light source coherent with said first light source; forming a second focused image of light reflected from said object on said photographic media superimposed on said first focused image; simultaneously illuminating said media with coherent light from said second source to record an interference pattern between such coherent light and said image on said media; developing said media to form a double exposure hologram; illuminating said hologram so as to reconstruct said first and second superimposed wavefronts; and modifying the manner of illumination of said hologram to adjust the phase of the first reconstructed wavefront relative to the second reconstructed wavefront by varying the angle of one of said reconstructing wavefronts relative to the photographic media.
Claim 12
Dependent Claim
63 words
The method of claim 7 wherein the two holograms were formed employing reference beams which made different angles with the photographic media, two reference beams are employed to reconstruct the two wavefronts and the position of the hologram relative to only one of the reference beams is varied in order to adjust the position of the two reconstructed wavefronts relative to one another.
Claim 13
Independent Claim
151 words
The method of performing holographic interferometric analysis of the deformation of an object between two times, comprising: forming a first image plane hologram of the object at the first time on a photographic plate using a first reference beam making a first angle relative to said photographic plate; forming a second image plane hologram of the object at a second time on said photographic plate, so as to be superimposed on said first hologram, using a second reference beam making a second angle relative to said photographic plate; reconstructing the wavefronts emanating from the object the first and second times from said hologram plate through use of first and second reconstructing beams which form different angles relative to the hologram plate; and varying the angle of at least one of said reconstructing beams relative to the hologram plate in order to modify the interference fringe density on the resultant superimposed image.
Claim 14
Independent Claim
151 words
The method of performing holographic interferometric analysis of the deformation of an object between two times, comprising: forming a first image plane hologram of the object at the first time on a photographic plate using a first reference beam making a first angle relative to said photographic plate; forming a second image plane hologram of the object at a second time on said photographic plate, so as to be superimposed on said first hologram, using a second reference beam making a second angle relative to said photographic plate; reconstructing the wavefronts emanating from the object the first and second times from said hologram plate through use of first and second reconstructing beams which form different angles relative to the hologram plate; and varying the angle of at least one of said reconstructing beams relative to the hologram plate in order to modify the interference fringe density on the resultant superimposed image.
Claim 15
Dependent Claim
37 words
The method of claim 9 wherein at least one of the reconstructing beams forms the same angle relative to the hologram plate as does one of the reference beams in the formation of the image plane holograms.
Claim 16
Dependent Claim
45 words
The method of claim 9 wherein lens means is employed between the object and the photographic plate during the formation of the first and second image plane holograms in order to focus an image of the object substantially at the plane of the photographic plate.
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) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |