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Holographic apparatus using incoherent light

Assignee: CDO-CONTROLE DIMENSIONNEL OPTIQUE
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Filing: 1990-04-20
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Granted: 1992-01-14
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Expires: 2010-04-20
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Abstract

Abstract A holographic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter inserted on the path of the light rays and wherein one of the birefringent crystal and the aperture angle limiter is disposed off the optical axis of the apparatus.

Inventors

  • 👤 Eric Dufresne
  • 👤 Pierre Chavel
  • 👤 Gabriel Sirat

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 17:32
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/04; G03H1/06; G03H1/0493

Claims Analysis

Total Claims: 44
Claim 1
Independent Claim 63 words
A holographic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter inserted on the path of the light rays and wherein the aperture angle limiter is situated off the optical axis of the apparatus and the birefringent crystal is placed on the optical axis of the apparatus.
Claim 2
Dependent Claim 63 words
A holographic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter inserted on the path of the light rays and wherein the aperture angle limiter is situated off the optical axis of the apparatus and the birefringent crystal is placed on the optical axis of the apparatus.
Claim 3
Dependent Claim 66 words
A holographic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter inserted on the path of the light rays and wherein the aperture angle limiter is centered on the optical axis of the apparatus, whereas the birefringent crystal has its axis inclined relative to the optical axis of the apparatus.
Claim 4
Dependent Claim 66 words
A holographic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter inserted on the path of the light rays and wherein the aperture angle limiter is centered on the optical axis of the apparatus, whereas the birefringent crystal has its axis inclined relative to the optical axis of the apparatus.
Claim 5
Dependent Claim 35 words
Apparatus according to claim 2, wherein the half angle at the apex of the aperture cone given by the limiter coincides with the inclination of the crystal relative to the optical axis of the apparatus.
Claim 6
Dependent Claim 13 words
Apparatus according to claim 2, wherein the aperture limiter includes an interference filter.
Claim 7
Dependent Claim 69 words
Apparatus according to claim 4, wherein the wavelength 1 at which the interference filter should be approached in order to eliminate a given angle 0 is given by the following equations: ##EQU2## in which: δλ represents the passband of the filter centered on the wavelength λ0 λα0 represents the resonance wavelength of the filter for the angle given that ##EQU3## N is the effective refractive index of the filter.
Claim 8
Dependent Claim 14 words
Apparatus according to claim 2, wherein the aperture angle limiter comprises a two-prism system.
Claim 9
Dependent Claim 26 words
Apparatus according to claim 6, wherein the two-prism system is constituted by a glass cube split into two identical portions separated by a layer of air.
Claim 10
Dependent Claim 53 words
Apparatus according to claim 6, wherein each of the prisms has an inlet face or an outlet face orthogonal to the plane defined by a ray and the optical axis of the system, and a working face orthogonal to said plane but inclined at an angle relative to said inlet or outlet face.
Claim 11
Dependent Claim 56 words
Apparatus according to claim 8, wherein the inclination of the working face relative to the inlet face or the outlet face is defined by the equation: Y=Arcisin [1/n]-i.sub.1 /n in which n represents the index of the prisms; and i 1 represents the inclination of the incident ray relative to the optical axis of the apparatus.
Claim 12
Dependent Claim 30 words
Apparatus according to claim 6, wherein the maximum angle to be eliminated coincides with the angle of inclination of the crystal axis relative to the optical axis of the apparatus.
Claim 13
Dependent Claim 19 words
Apparatus according to claim 6, comprising a plurality of two-prism systems distributed around the optical axis of the apparatus.
Claim 14
Dependent Claim 15 words
Apparatus according to claim 2, wherein the aperture angle limiter comprises a slab of fibers.
Claim 15
Dependent Claim 63 words
A holographic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter comprising a lens associated with a diaphragm, inserted on the path of the light rays and wherein one of the birefringent crystal and the aperture angle limiter is disposed off the optical axis of the apparatus.
Claim 16
Dependent Claim 63 words
A holographic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter comprising a lens associated with a diaphragm, inserted on the path of the light rays and wherein one of the birefringent crystal and the aperture angle limiter is disposed off the optical axis of the apparatus.
Claim 17
Dependent Claim 17 words
Apparatus according to claim 13, wherein the diaphragm is placed in the object plane of the lens.
Claim 18
Dependent Claim 57 words
Apparatus according to claim 13, wherein the aperture angle limiter is situated off the optical axis of the apparatus and the birefringent crystal is placed on the optical axis of the apparatus, and wherein the lens is centered on the optical axis of the apparatus and that the diaphragm is flush with the axis of the lens.
Claim 19
Dependent Claim 51 words
Apparatus according to claim 13, wherein the aperture angle limter is centered on the optical axis of the apparatus, whereas the birefringent crystal has its axis inclined relative to the optical axis of the apparatus, and wherein the lens and the diaphragm are centered on the optical axis of the apparatus.
Claim 20
Dependent Claim 24 words
Apparatus according to claim 16, wherein the main inlet and outlet faces of the crystal are perpendicular to the optical axis of the apparatus.
Claim 21
Dependent Claim 24 words
Apparatus according to claim 16, wherein the main inlet and outlet faces of the crystal are perpendicular to the optical axis of the crystal.
Claim 22
Dependent Claim 12 words
Apparatus according to claim 13, wherein the diaphragm is circular in section.
Claim 23
Dependent Claim 12 words
Apparatus according to claim 13, wherein the diaphragm is square in section.
Claim 24
Dependent Claim 21 words
Apparatus according to claim 13, wherein the transmittance of the diaphragm is variable as a function of the frequency under consideration.
Claim 25
Dependent Claim 64 words
Apparatus according to claim 13, including optical means such that the three dimensional extent E of the object seen through the aperture angle limiter satisfies the relationship: E<[dR/f]-0[1+d/f] in which: d represents the distance of the object from the diaphragm; R represents the radius of an elementary hologram; f representes the focal length of the lens; and 0 represents the dimeter of the diaphragm.
Claim 26
Dependent Claim 19 words
Apparatus according to claim 22, wherein the distance d of the object from the diaphragm satisfies the relationship: d>f0/[R-0].
Claim 27
Dependent Claim 20 words
Apparatus according to claim 22, wherein the optical means include a second lens placed upstream from the aperture angle limiter.
Claim 28
Dependent Claim 12 words
Apparatus according to claim 22, including a diaphragm in the object plane.
Claim 29
Dependent Claim 95 words
A holographic apparatus of the type comprising a conoscopic system including a birefrigent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter inserted on the path of the light rays, wherein the aperture angle limiter is centered on the optical axis of the apparatus, whereas the birefrigent crystal has its axis inclined relative to the optical axis of the apparatus, and wherein the half-angle at the apex of the aperture cone given by the limiter coincides with the inclination of the crystal relative to the optical axis of the apparatus.
Claim 30
Dependent Claim 95 words
A holographic apparatus of the type comprising a conoscopic system including a birefrigent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter inserted on the path of the light rays, wherein the aperture angle limiter is centered on the optical axis of the apparatus, whereas the birefrigent crystal has its axis inclined relative to the optical axis of the apparatus, and wherein the half-angle at the apex of the aperture cone given by the limiter coincides with the inclination of the crystal relative to the optical axis of the apparatus.
Claim 31
Dependent Claim 82 words
A holographic apparatus of the type comprising a conoscopic system including a birefrigent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter including an interference filter, inserted on the path of the light rays, and wherein the aperture angle limter is centered on the light rays, and wherein the aperture angle limiter is centered on the optical axis of the apparatus, whereas the birefringent crystal has its axis inclined relative to the optical axis of the apparatus.
Claim 32
Dependent Claim 82 words
A holographic apparatus of the type comprising a conoscopic system including a birefrigent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter including an interference filter, inserted on the path of the light rays, and wherein the aperture angle limter is centered on the light rays, and wherein the aperture angle limiter is centered on the optical axis of the apparatus, whereas the birefringent crystal has its axis inclined relative to the optical axis of the apparatus.
Claim 33
Dependent Claim 75 words
Apparatus according to claim 27, wherein the wavelength 1 at which the interference filter should be approached in order to eliminate a given angle o is given by the following equations: ##EQU4## in which: δ λ represents the passband of the filter centered on the wavelength λ o λ α 0 represents the resonance wavelength of the filter for the angle α o given that ##EQU5## N is the effective refractive index of the filter.
Claim 34
Dependent Claim 70 words
A holographic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter comprising a two-prism system, inserted on the path of the light rays and wherein the aperture angle limiter is centered on the optical axis of the apparatus, whereas the birefringent crystal has its axis inclined relative to the optical axis of the apparatus.
Claim 35
Dependent Claim 70 words
A holographic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter comprising a two-prism system, inserted on the path of the light rays and wherein the aperture angle limiter is centered on the optical axis of the apparatus, whereas the birefringent crystal has its axis inclined relative to the optical axis of the apparatus.
Claim 36
Dependent Claim 26 words
Apparatus according to claim 29, wherein the two-prism system is constituted by a glass cube split into two identical portions separated by a layer of air.
Claim 37
Dependent Claim 53 words
Apparatus according to claim 29, wherein each of the prisms has an inlet face or an outlet face orthogonal to the plane defined by a ray and the optical axis of the system, and a working face orthogonal to said plane but inclined at an angle relative to said inlet or outlet face.
Claim 38
Dependent Claim 56 words
Apparatus according to claim 31, wherein the inclination of the working face relative to the inlet face or the outlet face is defined by the equation: Y=Arcsin [1/n]-i.sub.1 /n in which n represents the index of the prisms; and i l represents the inclination of the incident ray relative to the optical axis of the apparatus.
Claim 39
Dependent Claim 30 words
Apparatus according to claim 29, wherein the maximum angle to be eliminated coincides with the angle of inclination of the crystal axis relative to the optical axis of the apparatus.
Claim 40
Dependent Claim 19 words
Apparatus according to claim 29, comprising a plurality of two-prism systems distribution around the optical axis of the apparatus.
Claim 41
Dependent Claim 71 words
A holoigraphic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between tow polarizers, wherein the apparatus also includes an aperture angle limiter comprising a slab of fibers, inserted on the path of the light rays and wherein the aperture angle limiter is centered on the optical axis of the apparatus, whereas the birefringent crystal has its axis inclined relative to the optical axis of the apparatus.
Claim 42
Dependent Claim 71 words
A holoigraphic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between tow polarizers, wherein the apparatus also includes an aperture angle limiter comprising a slab of fibers, inserted on the path of the light rays and wherein the aperture angle limiter is centered on the optical axis of the apparatus, whereas the birefringent crystal has its axis inclined relative to the optical axis of the apparatus.
Claim 43
Dependent Claim 105 words
A holographic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter inserted on the path of the light rays, wherein the aperture angle limiter is centered on the optical axis of the apparatus, whereas the birefringent crystal has its axis inclined relative to the optical axis of the apparatus, and wherein the inlet polarizer comprises a bipolarizing prism and a quarter-wave plate or equivalent optical valve, and by the fact that a second recording medium is placed facing the bipolarizing prism to record a two-dimensional image of the object.
Claim 44
Dependent Claim 105 words
A holographic apparatus of the type comprising a conoscopic system including a birefringent crystal inserted between two polarizers, wherein the apparatus also includes an aperture angle limiter inserted on the path of the light rays, wherein the aperture angle limiter is centered on the optical axis of the apparatus, whereas the birefringent crystal has its axis inclined relative to the optical axis of the apparatus, and wherein the inlet polarizer comprises a bipolarizing prism and a quarter-wave plate or equivalent optical valve, and by the fact that a second recording medium is placed facing the bipolarizing prism to record a two-dimensional image of the object.

References Cited (Backward Citations)

US3558207A Cited
US4602844A Cited
US4976504A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-01-13 1995-07-15 1996-01-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-01-13 1999-07-15 2000-01-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-01-13 2003-07-15 2004-01-14 $7700.00 Window Closed / Lapsed

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