Patent US3832026A successfully refreshed from Google Patents.
US3832026A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Holography using light of limited coherence
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1972-05-11
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Granted: 1974-08-27
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Expires: 1992-05-11
Abstract
Abstract A method is disclosed for forming good quality holograms using light of only limited coherence. According to the method, a hologram plate is illuminated by a reference laser beam and by laser light scattered from an object of which a hologram is to be formed. Local intensity fluctuations having maxima and minima are formed at the object for each frequency of light in the laser beam. Good holograms are formed provided that the intensity maxima belonging to one frequency of the laser light do not predominantly coincide with the intensity maxima of any other frequency of the laser light.
Inventors
- 👤 F Mottier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 23:18
CPC Classifications
G; G03; G03H; G03H1/00; G03H1/04; G03H1/06; Y; Y10; Y10S; Y10S359/00; Y10S359/90
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
220 words
A method of producing holograms using light of limited coherence comprising the steps of: providing a laser light beam, illuminating a hologram recording plate with a first portion of said laser light beam, providing a second portion of said laser light beam for illuminating an object of which a hologram is to be formed, splitting said second portion of said light beam into two subsidiary beams, directing said two subsidiary beams in a respectively inclined relationship onto said object over a path length for one of said subsidiary beams which differs from the path length of the other of said subsidiary beams by at least one coherence length of said laser light; illuminating said hologram plate with light scattered from said object, arranging said object in the path of said two respectively inclined subsidiary beams to produce local intensity fluctuation having maxima and minima at said object, said local intensity fluctuations corresponding to each frequency of light present in said light from said subsidiary beams such that the intensity maxima at any point on said object corresponding to one frequency of said laser light do not predominantly coincide with the intensity maxima of any other frequency in said laser light, whereby the contrast in the speckle pattern from said object recorded at said hologram plate under the illumination in minimized.
Claim 2
Independent Claim
220 words
A method of producing holograms using light of limited coherence comprising the steps of: providing a laser light beam, illuminating a hologram recording plate with a first portion of said laser light beam, providing a second portion of said laser light beam for illuminating an object of which a hologram is to be formed, splitting said second portion of said light beam into two subsidiary beams, directing said two subsidiary beams in a respectively inclined relationship onto said object over a path length for one of said subsidiary beams which differs from the path length of the other of said subsidiary beams by at least one coherence length of said laser light; illuminating said hologram plate with light scattered from said object, arranging said object in the path of said two respectively inclined subsidiary beams to produce local intensity fluctuation having maxima and minima at said object, said local intensity fluctuations corresponding to each frequency of light present in said light from said subsidiary beams such that the intensity maxima at any point on said object corresponding to one frequency of said laser light do not predominantly coincide with the intensity maxima of any other frequency in said laser light, whereby the contrast in the speckle pattern from said object recorded at said hologram plate under the illumination in minimized.
Claim 3
Dependent Claim
40 words
A method of producing holograms using light of limited coherence as in claim 1, further comprising the step of: causing said maxima and minima of said intensity fluctuations to have an extent which is below the level of optical resolution.
Claim 4
Independent Claim
189 words
A method of producing holograms using light of limited coherence comprising the steps of: providing a first laser light beam, illuminating a hologram recording plate with said first laser light beam, providing a second laser light beam for illuminating an object of which a hologram is to be formed, directing said second laser light beam onto a diffusely scattering body for causing said diffusely scattering body to illuminate a given point on said object with at least two beams of light, the path lengths of which differ by at least one coherence length of said laser light, said step of directing including the step of producing local intensity fluctuations having maxima and minima at said object, said local intensity fluctuations corresponding to each frequency of said laser light scattered from said diffusely scattering body such that the intensity maxima at any point on said object corresponding to one frequency of said laser light do not predominantly coincide with the intensity maxima of any other frequency in said laser light, whereby the contrast in the speckle pattern from said object recorded at said hologram plate under the illumination in minimized.
Claim 5
Independent Claim
189 words
A method of producing holograms using light of limited coherence comprising the steps of: providing a first laser light beam, illuminating a hologram recording plate with said first laser light beam, providing a second laser light beam for illuminating an object of which a hologram is to be formed, directing said second laser light beam onto a diffusely scattering body for causing said diffusely scattering body to illuminate a given point on said object with at least two beams of light, the path lengths of which differ by at least one coherence length of said laser light, said step of directing including the step of producing local intensity fluctuations having maxima and minima at said object, said local intensity fluctuations corresponding to each frequency of said laser light scattered from said diffusely scattering body such that the intensity maxima at any point on said object corresponding to one frequency of said laser light do not predominantly coincide with the intensity maxima of any other frequency in said laser light, whereby the contrast in the speckle pattern from said object recorded at said hologram plate under the illumination in minimized.
Claim 6
Dependent Claim
57 words
A method of producing holograms using light of limited coherence as in claim 3 further comprising the steps: of selecting the dimensions of said diffusely scattering body and arranging its position in said second laser light beam to provide said path length difference of at least one coherence length between said at least two beams of light.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-26 | 1978-02-25 | 1978-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-26 | 1982-02-25 | 1982-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-26 | 1986-02-25 | 1986-08-27 | $7700.00 | Window Closed / Lapsed |