US3844660A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for aligning an interferometer mirror
Assignee: Zygo Corp
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Filing: 1972-11-16
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Granted: 1974-10-29
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Expires: 1992-11-16
Abstract
Abstract A method and apparatus for aligning an interferometer mirror orthogonal to an incident collimated light beam is described. A retroreflector is placed in the collimated beam before the mirror so that a reference beam is obtained to which the light reflected by the interferometer mirror can be aligned on the view screen of the interferometer. Once adjustment has been achieved, the retroreflector can be removed.
Inventors
- 👤 G Hunter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:50
CPC Classifications
G; G01; G01B; G01B9/00; G01B9/02; G01B9/02055; G01B9/02056; G01B9/02057; G01B9/02061; G01B9/0207; G01B9/02072
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
193 words
The method of aligning an interferometer comprising a light source, a first lens which focuses the light and a second lens which collimates the light into a beam which falls onto an adjustable partially reflecting mirror which can be adjusted to be orthogonal to said beam, and a beam splitter between the two lenses in the optical path formed by said light source, said lenses and said mirror, which beam splitter directs light reflected from said mirror onto a viewing screen out of said optical path, in which said mirror must be adjusted exactly orthogonal to the collimated beam to align the interferometer, which method comprises interrupting a portion of said beam between said second lens and said mirror and retroreflecting the interrupted portion of the beam exactly parallel to its incidence, thereby providing a spot of light on said viewing screen at the exact position where the reflected light from said mirror would focus if said mirror were exactly orthogonal to said beam, and adjusting the angle of said mirror so that the spot of light reflected from said mirror onto said screen coincides with the spot from the reflected interrupted beam.
Claim 2
Independent Claim
193 words
The method of aligning an interferometer comprising a light source, a first lens which focuses the light and a second lens which collimates the light into a beam which falls onto an adjustable partially reflecting mirror which can be adjusted to be orthogonal to said beam, and a beam splitter between the two lenses in the optical path formed by said light source, said lenses and said mirror, which beam splitter directs light reflected from said mirror onto a viewing screen out of said optical path, in which said mirror must be adjusted exactly orthogonal to the collimated beam to align the interferometer, which method comprises interrupting a portion of said beam between said second lens and said mirror and retroreflecting the interrupted portion of the beam exactly parallel to its incidence, thereby providing a spot of light on said viewing screen at the exact position where the reflected light from said mirror would focus if said mirror were exactly orthogonal to said beam, and adjusting the angle of said mirror so that the spot of light reflected from said mirror onto said screen coincides with the spot from the reflected interrupted beam.
Claim 3
Dependent Claim
31 words
The method of claim 1, in which the amounts of light reflected onto the screen from the -interrupted beam- and mirror are adjusted so that they approximate each other in intensity.
Claim 4
Dependent Claim
147 words
In an interferometer apparatus comprising a light source, a first lens which focuses and expands the light, a second lens which collimates the light into a collimated beam, a partially reflecting mirror which receives said collimated beam and reflects a portion of said beam back into the apparatus, said mirror being adjustable into a position orthogonal to said beam, a beam splitter between said lenses in the optical path formed by said light source, said lenses and said mirror, which beam splitter directs said reflected beam onto a viewing screen out of said optical path, the improvement which comprises a cube corner retroreflector in said optical path between said second lens and said mirror which reflects a spot of light onto the viewing screen at exactly the point on the viewing screen where light from said mirror falls when said mirror is orthogonal to said collimated beam.
Claim 5
Dependent Claim
147 words
In an interferometer apparatus comprising a light source, a first lens which focuses and expands the light, a second lens which collimates the light into a collimated beam, a partially reflecting mirror which receives said collimated beam and reflects a portion of said beam back into the apparatus, said mirror being adjustable into a position orthogonal to said beam, a beam splitter between said lenses in the optical path formed by said light source, said lenses and said mirror, which beam splitter directs said reflected beam onto a viewing screen out of said optical path, the improvement which comprises a cube corner retroreflector in said optical path between said second lens and said mirror which reflects a spot of light onto the viewing screen at exactly the point on the viewing screen where light from said mirror falls when said mirror is orthogonal to said collimated beam.
Claim 6
Dependent Claim
13 words
The apparatus of claim 3, in which the light source is a laser.
References Cited (Backward Citations)
US3528748A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |