US3776636A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for investigating the coherence of light radiation
Assignee: BBC Brown Boveri AG Switzerland
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Filing: 1972-02-22
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Granted: 1973-12-04
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Expires: 1992-02-22
Abstract
Abstract A process and an apparatus are disclosed for examining the mode structure or coherence of laser light beams. According to the process, the laser beam to be studied is first divided into two portions which are projected onto a diffusely scattering body in a superimposed fashion. If the laser beam is not coherent, patterns are formed on the scattering body which are visually observable. No visible interference fringes are formed if the laser beam is strictly coherent. The apparatus disclosed includes a beam splitter for dividing the laser beam into two portions, and an optical system for projecting the two beam portions onto a diffusely scattering body. The diffusely scattering body may be comprised of a variety of materials, such as white paper, and may include a calibrating scale.
Inventors
- 👤 R Dandliker
- 👤 F Mottier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:04
CPC Classifications
G; G01; G01J; G01J9/00; G01J9/02
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
64 words
An apparatus for studying the coherence of laser beams, comprising: means for producing a laser beam; optical means for splitting said laser beam into at least two portions; means for diffusely scattering incident light beams; means for projecting said two beam portions onto said diffusely scattering means in a mutually inclined fashion; and means for observing any patterns produced on said diffusely scattering means.
Claim 2
Independent Claim
64 words
An apparatus for studying the coherence of laser beams, comprising: means for producing a laser beam; optical means for splitting said laser beam into at least two portions; means for diffusely scattering incident light beams; means for projecting said two beam portions onto said diffusely scattering means in a mutually inclined fashion; and means for observing any patterns produced on said diffusely scattering means.
Claim 3
Dependent Claim
29 words
An apparatus for studying the coherence of laser beams as in claim 1, wherein: said means for projecting said two beam portions includes a plurality of optically clear elements.
Claim 4
Dependent Claim
36 words
An apparatus for studying the coherence of laser beams as in claim 1, wherein: said two beam portions are of equal intensity; and said means for projecting said two beam portions includes deflecting mirrors and lenses.
Claim 5
Dependent Claim
29 words
An apparatus for studying the coherence of laser beams as in claim 1, wherein: said means for projecting said two beam portions includes a plurality of diffusely scattering bodies.
Claim 6
Dependent Claim
59 words
An apparatus for studying the coherence of laser beams as in claim 3, wherein: said diffusely scattering means includes a planar surface having a length equal to at least C/2 Delta Nu ; and, said beam portions are inclined with respect to one another and with respect to said planar surface so that said planar surface is entirely illuminated.
Claim 7
Dependent Claim
57 words
An apparatus for studing the coherence of laser beams as in claim 1, wherein: said means for projecting said two beam portions includes adjustable reflecting means positioned in the path of one of said beam portions for varying the distance traveled by said one beam portion to said diffusely scattering means, whereby desired path differences are produced.
Claim 8
Dependent Claim
42 words
An apparatus for studying the coherence of laser beams as in claim 1, wherein: said diffusely scattering means includes a first region illuminated by both of said two beam portions and a second region illuminated by only one of said beam portions.
Claim 9
Dependent Claim
38 words
An apparatus for studying the coherence of laser beams as in claim 1, wherein: said diffusely scattering means includes a scale for measuring dimensions on an illuminated surface thereof; and said scale is observable by said Observing means.
Claim 10
Dependent Claim
27 words
An apparatus for studying the coherence of laser beams as in claim 6, further comprising: a scale associated with said adjustable reflecting means for measuring movements thereof.
Claim 11
Dependent Claim
73 words
An apparatus for studying the coherence of laser beams as in claim 1, wherein: rays of said two beam portions impinging at the same point of said diffusely scattering means have path differences in the range from zero to at least C/2 Delta Nu , where C is the velocity of light and Delta Nu is the frequency bandwidth of the light radiation within which the coherence study is to be carried out.
References Cited (Backward Citations)
US3641343A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-03 | 1977-06-04 | 1977-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-03 | 1981-06-04 | 1981-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-03 | 1985-06-04 | 1985-12-04 | $7700.00 | Window Closed / Lapsed |