US4746216A
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Angle measuring interferometer
Assignee: Zygo Corp
•
Filing: 1986-06-12
•
Granted: 1988-05-24
•
Expires: 2006-06-12
Abstract
Abstract An angle measuring interferometer comprises a source (10) which emits a light beam containing two linear orthogonally polarized components; means, such as a tilted shear plate (16) or a beamsplitter/beam folder assembly (116, 116A) for converting the input beam into two separated, parallel, orthogonally polarized beams; a half-wave retardation plate (29A, 29) located in one of the separated beams for converting the two separated parallel orthogonally polarized beams into two separated parallel beams with the same polarization; means including a polarizing beamsplitter (44), for causing each of the separated parallel beams with the same polarization to be reflected once by each of two plane mirrors (71, 70) to produce two parallel output beams with the same polarization; a half-wave retardation plate (29B, 29) located in one of the separated parallel output beams, for converting the two separated parallel output beams of the same polarization into two separated parallel output beams with orthogonal polarization, with means, such as the tilted shear plate (16) or the beamsplitter/beam folder assembly (116, 116B), converting the two separated parallel orthogonally polarized output beams into a single output beam in which the phase difference, "δ", between the two polarization components of the single output beam is directly proportional to the angle, "θ", between the two plane mirrors (70, 71); a polarizer (81) for mixing the orthogonal components of the output beam; a photoelectric detector (83) to produce the measurement signal; and an electronic module (90) to indicate the phase difference, "Δδ", which is directly proportional to the changes in the angular orientation, "Δθ", between the two plane mirrors (70, 71).
Inventors
- 👤 Gary E. Sommargren
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:09
CPC Classifications
G; G01; G01B; G01B11/00; G01B11/26; G01B9/00; G01B9/02; G01B9/02015; G01B9/02017; G01B9/02019; G01B9/02055; G01B9/02056; G01B9/02057; G01B9/02075; G01B9/02076; G01B2290/00; G01B2290/70
Claims Analysis
Total Claims: 138
Claim 1
Independent Claim
321 words
An angle measuring plane mirror interferometric system comprising: a pair of plane mirrors being angularly variable with respect to each other by a variable angle between said pair of plane mirrors; source means for emitting an input beam comprising two stabilized orthogonally polarized optical frequencies; means optically coupled to said input beam for converting said input beam into two separated parallel orthogonally polarized beams; means optically disposed in the path of one of said two separated parallel orthogonally polarized beams for converting said two separated parallel orthogonally polarized beams into two separated parallel beams having the same polarization; means optically coupled to said two separated parallel same polarized beams for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors to produce two parallel output beams having the same polarization; means optically disposed in the path of one of said two separated same polarized parallel output beams for converting said two separated same polarized parallel output beams into two separated orthogonally polarized parallel output beams; means optically coupled to said two separated parallel orthogonally polarized output beams for converting said two separated parallel orthogonally polarized output beams into a single output beam having a pair of orthogonally polarized frequency components, with a phase difference therebetween being directly proportional to said variable angle between said pair of plane mirrors; means optically coupled to said single output beam for mixing said orthogonally polarized components thereof and producing an electrical measurement signal therefrom; and means operatively connected to said electrical measurement signal for extracting a difference in phase from said electrical measurement signal, variations in said extracted phase difference being proportional to angular changes in said variable angle between said pair of plane mirrors; whereby an optical configuration in which the angular measurements are extremely insensitive to three dimensional displacement of said plane mirrors is provided for said interferometric system.
Claim 2
Dependent Claim
321 words
An angle measuring plane mirror interferometric system comprising: a pair of plane mirrors being angularly variable with respect to each other by a variable angle between said pair of plane mirrors; source means for emitting an input beam comprising two stabilized orthogonally polarized optical frequencies; means optically coupled to said input beam for converting said input beam into two separated parallel orthogonally polarized beams; means optically disposed in the path of one of said two separated parallel orthogonally polarized beams for converting said two separated parallel orthogonally polarized beams into two separated parallel beams having the same polarization; means optically coupled to said two separated parallel same polarized beams for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors to produce two parallel output beams having the same polarization; means optically disposed in the path of one of said two separated same polarized parallel output beams for converting said two separated same polarized parallel output beams into two separated orthogonally polarized parallel output beams; means optically coupled to said two separated parallel orthogonally polarized output beams for converting said two separated parallel orthogonally polarized output beams into a single output beam having a pair of orthogonally polarized frequency components, with a phase difference therebetween being directly proportional to said variable angle between said pair of plane mirrors; means optically coupled to said single output beam for mixing said orthogonally polarized components thereof and producing an electrical measurement signal therefrom; and means operatively connected to said electrical measurement signal for extracting a difference in phase from said electrical measurement signal, variations in said extracted phase difference being proportional to angular changes in said variable angle between said pair of plane mirrors; whereby an optical configuration in which the angular measurements are extremely insensitive to three dimensional displacement of said plane mirrors is provided for said interferometric system.
Claim 3
Dependent Claim
43 words
An angle measuring plane mirror interferometric system in accordance with claim 1 wherein said means for converting said two separated parallel orthogonally polarized output beams into said single output beam having said pair of orthogonally polarized frequency components comprises a shear plate means.
Claim 4
Dependent Claim
98 words
An angle measuring plane mirror interferometric system in accordance with claim 2, wherein said shear plate means comprises means for providing said pair of orthogonally polarized frequency components with said phase difference "δ" in accordance with the expression ##EQU7## where "h" is the thickness of said shear plate, "n" is the refractive index of said shear plate, "λ" is the wavelength of said input beam source means, "α" is the angle of incidence of said input beam on said shear plate and "θ" is the angular tilt of said pair of plane mirrors with respect to each other.
Claim 5
Dependent Claim
39 words
An angle measuring plane mirror interferometric system in accordance with claim 3 wherein said angular change "Δθ" for small variations in said angular tilt is defined by the expression ##EQU8## where "Δδ" is the variation in said phase difference.
Claim 6
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 3 wherein said source means comprises a laser.
Claim 7
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 5 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 8
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 3 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 9
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 14 wherein said source means comprises a laser.
Claim 10
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 8 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 11
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 14 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 12
Dependent Claim
23 words
An angle measuring plane mirror interferometric system in accordance with claim 2 wherein said shear plate means comprises a tilted shear plate means.
Claim 13
Dependent Claim
99 words
An angle measuring plane mirror interferometric system in accordance with claim 11 wherein said tilted shear plate means comprises means for providing said pair of orthogonally polarized frequency components with said phase difference "δ" in accordance with the expression ##EQU9## where "h" is the thickness of said shear plate, "n" is the refractive index of said shear plate, "λ" is the wavelength of said input beam source means, "α" is the angle of incidence of said input beam on said shear plate and "θ" is the angular tilt of said pair of plane mirrors with respect to each other.
Claim 14
Dependent Claim
39 words
An angle measuring plane mirror interferometric system in accordance with claim 12 wherein said angular change "Δθ" for small variations in said angular tilt is defined by the expression ##EQU10## where "Δδ" is the variation in said phase difference.
Claim 15
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 13 wherein said source means comprises a laser.
Claim 16
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 12 wherein said source means comprises a laser.
Claim 17
Dependent Claim
33 words
An angle measuring plane mirror interferometric system in accordance with claim 1 wherein said source means emits said input beam comprising two stabilized orthogonally polarized optical frequencies which are of the same value.
Claim 18
Dependent Claim
43 words
An angle measuring plane mirror interferometric system in accordance with claim 16 wherein said means for converting said two separated parallel orthogonally polarized output beams into said single output beam having said pair of orthogonally polarized frequency components comprises a shear plate means.
Claim 19
Dependent Claim
98 words
An angle measuring plane mirror interferometric system in accordance with claim 17 wherein said shear plate means comprises means for providing said pair of orthogonally polarized frequency components with said phase difference "δ" in accordance with the expression ##EQU11## where "h" is the thickness of said shear plate, "n" is the refractive index of said shear plate, "λ" is the wavelength of said input beam source means, "α" is the angle of incidence of said input beam on said shear plate and "θ" is the angular tilt of said pair of plane mirrors with respect to each other.
Claim 20
Dependent Claim
39 words
An angle measuring plane mirror interferometric system in accordance with claim 18 wherein said angular change "Δθ" for small variations in said angular tilt is defined by the expression ##EQU12## where "Δθ" is the variation in said phase difference.
Claim 21
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 18 wherein said source means comprises a laser.
Claim 22
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 20 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 23
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 18 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 24
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 19 wherein said source means comprises a laser.
Claim 25
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 23 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 26
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 19 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 27
Dependent Claim
23 words
An angle measuring plane mirror interferometric system in accordance with claim 17 wherein said shear plate means comprises a tilted shear plate means.
Claim 28
Dependent Claim
99 words
An angle measuring plane mirror interferometric system in accordance with claim 26 wherein said tilted shear plate means comprises means for providing said pair of orthogonally polarized frequency components with said phase difference "θ" in accordance with the expression ##EQU13## where "h" is the thickness of said shear plate, "n" is the refractive index of said shear plate, "λ" is the wavelength of said input beam source means, "α" is the angle of incidence of said input beam on said shear plate and "θ" is the angular tilt of said pair of plane mirrors with respect to each other.
Claim 29
Dependent Claim
39 words
An angle measuring plane mirror interferometric system in accordance with claim 27 wherein said angular change "Δθ" for small variations in said angular tilt is defined by the expression ##EQU14## where "Δθ" is the variation in said phase difference.
Claim 30
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 28 wherein said source means comprises a laser.
Claim 31
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 27 wherein said source means comprises a laser.
Claim 32
Dependent Claim
90 words
An angle measuring plane mirror interferometric system in accordance with claim 11 wherein said tilted shear plate means comprises a first set of regions of antireflection and polarizing coatings, said means for converting said two separated parallel orthogonally polarized output beams into said single output mean comprising said first set of regions and coatings on said tilted shear plate means, said tilted shear plate means further comprising a second set of regions of antireflection and polarization coatings, said second set of regions and coatings comprising said input beam converting means.
Claim 33
Dependent Claim
90 words
An angle measuring plane mirror interferometric system in accordance with claim 26 wherein said tilted shear plate means comprises a first set of regions of antireflection and polarizing coatings, said means for converting said two separated parallel orthogonally polarized output beams into said single output mean comprising said first set of regions and coatings on said tilted shear plate means, said tilted shear plate means further comprising a second set of regions of antireflection and polarization coatings, said second set of regions and coatings comprising said input beam converting means.
Claim 34
Dependent Claim
38 words
An angle measuring plane mirror interferometric system in accordance with claim 2 wherein said means for converting said two separated parallel orthogonally polarized beams into said two same polarized separated parallel beams comprises a half-wave retardation plate means.
Claim 35
Dependent Claim
38 words
An angle measuring plane mirror interferometric system in accordance with claim 17 wherein said means for converting said two separated parallel orthogonally polarized beams into said two same polarized separated parallel beams comprises a half-wave retardation plate means.
Claim 36
Dependent Claim
50 words
A angle measuring plane mirror interferometric system in accordance with claim 2 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors comprises a polarizing beam splitter means and a retroreflector means.
Claim 37
Dependent Claim
47 words
An angle measuring plane mirror interferometric system in accordance with claim 35 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors further comprises a quarter-wave retardation plate means.
Claim 38
Dependent Claim
50 words
An angle measuring plane mirror interferometric system in accordance with claim 17 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors comprises a polarizing beam splitter means and a retroreflector means.
Claim 39
Dependent Claim
47 words
An angle measuring plane mirror interferometric system in accordance with claim 37 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors further comprises a quarter-wave retardation plate means.
Claim 40
Dependent Claim
40 words
An angle measuring plane mirror interferometric system in accordance with claim 2 wherein said means for converting said two separated parallel same polarized output beams into said two separated parallel orthogonally polarized output beams comprises a half-wave retardation plate means.
Claim 41
Dependent Claim
40 words
An angle measuring plane mirror interferometric system in accordance with claim 17 wherein said means for converting said two separated parallel same polarized output beams into said two separated parallel orthogonally polarized output beams comprises a half-wave retardation plate means.
Claim 42
Dependent Claim
33 words
An angle measuring plane mirror interferometric system in accordance with claim 2 wherein said means for producing said electrical measurement signal comprises a polarizer means for mixing said single output beam orthogonal components.
Claim 43
Dependent Claim
26 words
An angle mesuring plane mirror interferometric system in accordance with claim 41 wherein said means for producing said electrical measurement signal further comprises a photoelectric detector.
Claim 44
Dependent Claim
33 words
An angle measuring plane mirror interferometric system in accordance with claim 17 wherein said means for producing said electrical measurement signal comprises a polarizer means for mixing said single ouput beam orthogonal components.
Claim 45
Dependent Claim
33 words
An angle measuring plane mirror interferometric system in accordance with claim 43 wherein said means for producing said electrical measurement signal comprises a polarizer means for mixing said single output beam orthogonal components.
Claim 46
Dependent Claim
38 words
An angle measuring plane mirror interferometric system in accordance with claim 31 wherein said means for converting said two separated parallel orthogonally polarized beams into said two same polarized separated parallel beams comprises a half-wave retardation plate means.
Claim 47
Dependent Claim
38 words
An angle measuring plane mirror interferometric system in accordance with claim 32 wherein said means for converting said two separated parallel orthogonally polarized beams into said two same polarized separated parallel beams comprises a half-wave retardation plate means.
Claim 48
Dependent Claim
50 words
An angle measuring plane mirror interferometric system in accordance with claim 31 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors comprises a polarizing beam splitter means and a retroreflector means.
Claim 49
Dependent Claim
50 words
An angle measuring plane mirror interferometric system in accordance with claim 47 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors comprise a polarizing beam splitter means and a retroreflector means.
Claim 50
Dependent Claim
40 words
An angle measuring plane mirror interferometric system in accordance with claim 48 wherein said means for converting said two separated parallel same polarized output beams into said two separated parallel orthogonally polarized output beams comprises a half-wave retardation plate means.
Claim 51
Dependent Claim
33 words
An angle measuring plane mirror interferometric system in accordance with claim 49 wherein said means for producing said electrical measurement signal comprises a polarizer means for mixing said single output beam orthogonal components.
Claim 52
Dependent Claim
50 words
An angle measuring plane mirror interferometric system in accordance with claim 19 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors comprises a polarizing beam splitter means and a retroreflector means.
Claim 53
Dependent Claim
50 words
An angle measuring plane mirror interferometric system in accordance with claim 51 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors comprises a polarizing beam splitter means and a retroreflector means.
Claim 54
Dependent Claim
40 words
An angle measuring plane mirror interferometric system in accordance with claim 53 wherein said means for converting said two separated parallel same polarized output beams into said two separated parallel orthogonally polarized output beams comprises a half-wave retardation plate means.
Claim 55
Dependent Claim
33 words
An angle measuring plane mirror interferometric system in accordance with claim 53 wherein said means for producing said electrical measurement signal comprises a polarizer means for mixing said single output beam orthogonal components.
Claim 56
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 2 wherein said source means comprises a laser.
Claim 57
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 17 wherein said source means comprises a laser.
Claim 58
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 2 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 59
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 57 wherein said source means comprises a laser.
Claim 60
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 17 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 61
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 59 wherein said source means comprises a laser.
Claim 62
Dependent Claim
22 words
An angle measuring plane mirror interferometric system in accordance with claim 2 wherein all of said beams are in a single plane.
Claim 63
Dependent Claim
31 words
An angle measuring plane mirror interferometric system in accordance with claim 61 wherein all of said beams are optical beams and all of said optical beams are in a single plane.
Claim 64
Dependent Claim
22 words
An angle measuring plane mirror interferometric system in accordance with claim 17 wherein all of said beams are in a single plane.
Claim 65
Dependent Claim
31 words
An angle measuring plane mirror interferometric system in accordance with claim 63 wherein all of said beams are optical beams and all of said optical beams are in a single plane.
Claim 66
Dependent Claim
28 words
An angle measuring plane mirror interferometric system in accordance with claim 31 wherein said tilted shear plate comprises both said first and second set of regions and coatings.
Claim 67
Dependent Claim
43 words
An angle measuring plane mirror interferometric system in accordance with claim 65 wherein said tilted shear plate means comprises a tilted glass substrate having mutually parallel optically flat surfaces, with said sets of regions and coatings being disposed on said optically flat surfaces.
Claim 68
Dependent Claim
28 words
An angle measuring plane mirror interferometric system in accordance with claim 32 wherein said tilted shear plate comprises both said first and second set of regions and coatings.
Claim 69
Dependent Claim
43 words
An angle measuring plane mirror interferometric system in accordance with claim 67 wherein said tilted shear plate means comprises a tilted glass substrate having mutually parallel optically flat surfaces, with said sets of regions and coatings being disposed on said optically flat surfaces.
Claim 70
Dependent Claim
43 words
An angle measuring plane mirror interferometric system in accordance with claim 31 wherein said tilted shear plate means comprises a tilted glass substrate having mutually parallel optically flat surfaces, with said set of regions and coatings being disposed on said optically flat surfaces.
Claim 71
Dependent Claim
43 words
An angle measuring plane mirror interferometric system in accordance with claim 32 wherein said tilted shear plate means comprises a tilted glass substrate having mutually parallel optically flat surfaces, with said sets of regions and coatings being disposed on said optically flat surfaces.
Claim 72
Dependent Claim
29 words
An angle measuring plane mirror interferometric system in accordance with claim 11 wherein said tilted shear plate means comprises a tilted glass substrate having mutually parallel optically flat surfaces.
Claim 73
Dependent Claim
29 words
An angle measuring plane mirror interferometric system in accordance with claim 26 wherein said tilted shear plate means comprises a tilted glass substrate having mutually parallel optically flat surfaces.
Claim 74
Dependent Claim
22 words
An angle measuring plane mirror interferometric system in accordance with claim 11 wherein all of said beams are in a single plane.
Claim 75
Dependent Claim
31 words
An angle measuring plane mirror interferometric system in accordance with claim 73 wherein all of said beams are optical beams and all of said optical beams are in a single plane.
Claim 76
Dependent Claim
22 words
An angle measuring plane mirror interferometric system in accordance with claim 26 wherein all of said beams are in a single plane.
Claim 77
Dependent Claim
31 words
An angle measuring plane mirror interferometric system in accordance with claim 75 wherein all of said beams are optical beams and all of said optical beams are in a single plane.
Claim 78
Dependent Claim
33 words
An angle measuring plane mirror interferometric system in accordance with claim 1 wherein said means for converting said input beam into two separated parallel orthogonally polarized beams comprises a beamsplitter/beam folder assembly means.
Claim 79
Dependent Claim
26 words
An angle measuring plane mirror interferometer in accordance with claim 73 wherein said beamsplitter/beam folder assembly means comprises a right angle prism and a rhomboid prism.
Claim 80
Dependent Claim
56 words
An angle measuring plane mirror interferometric system in accordance with claim 77 wherein said beamsplitter/beam folder assembly means comprises a first set of regions of antireflection and polarizing coatings, said means for converting said input beam into said separated parallel orthogonally polarized output beams comprising said beamsplitter/beam folder assembly means first set of regions and coatings.
Claim 81
Dependent Claim
56 words
An angle measuring plane mirror interferometric system in accordance with claim 79 wherein said beamsplitter/beam folder assembly means comprises a first set of regions of antireflection and polarizing coatings, said means for converting said input beam into said separated parallel orthogonally polarized output beams comprising said beamsplitter/beam folder assembly means first set of regions and coatings.
Claim 82
Dependent Claim
34 words
An angle measuring plane mirror interferometric system in accordance with claim 16 wherein said means for converting said input beam into said two separated parallel orthogonally polarized beams comprises a beamsplitter/beam folder assembly means.
Claim 83
Dependent Claim
26 words
An angle measuring plane mirror interferometer in accordance with claim 81 wherein said beamsplitter/beam folder assembly means comprises a right angle prism and a rhomboid prism.
Claim 84
Dependent Claim
56 words
An angle measuring plane mirror interferometric system in accordance with claim 81 wherein said beamsplitter/beam folder assembly means comprises a first set of regions of antireflection and polarizing coatings, said means for converting said input beam into said separated parallel orthogonally polarized output beams comprising said beamsplitter/beam folder assembly means first set of regions and coatings.
Claim 85
Dependent Claim
56 words
An angle measuring plane mirror interferometric system in accordance with claim 83 wherein said beamsplitter/beam folder assembly means comprises a first set of regions of antireflection and polarizing coatings, said means for converting said input beam into said separated parallel orthogonally polarized output beams comprising said beamsplitter/beam folder assembly means first set of regions and coatings.
Claim 86
Dependent Claim
38 words
An angle measuring plane mirror interferometric system in accordance with claim 1 wherein said means for converting said two separated parallel orthogonally polarized beams into said two same polarized separated parallel beams comprises a half-wave retardation plate means.
Claim 87
Dependent Claim
37 words
An angle measuring plane mirror interferometric system in accordance with claim 16 wherein said means for converting said two separated parallel orthogonally polarized beams into said two polarized separated parallel beams comprises a half-wave retardation plate means.
Claim 88
Dependent Claim
48 words
An angle measuring interferometric system in accordance with claim 1 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors comprises a polarizing beam splitter means and a retroreflector means.
Claim 89
Dependent Claim
47 words
An angle measuring plane mirror interferometric system in accordance with claim 87 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors further comprises a quarter-wave retardation plate means.
Claim 90
Dependent Claim
50 words
An angle measuring plane mirror interferometric system in accordance with claim 16 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly varaible plane mirrors comprises a polarizing beam splitter means and a retroreflector means.
Claim 91
Dependent Claim
47 words
An angle measuring plane mirror interferometric system in accordance with claim 89 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors further comprises a quarter-wave retardation plate means.
Claim 92
Dependent Claim
40 words
An angle measuring plane mirror interferometric system in accordance with claim 1 wherein said means for converting said two separated parallel same polarized output beams into said two separated parallel orthogonally polarized output beams comprises a half-wave retardation plate means.
Claim 93
Dependent Claim
40 words
An angle measuring plane mirror interferometric system in accordance with claim 16 wherein said means for converting said two separated parallel same polarized output beams into said two separated parallel orthogonally polarized output beams comprises a half-wave retardation plate means.
Claim 94
Dependent Claim
33 words
An angle measuring plane mirror interferometric system in accordance with claim 1 wherein said means for producing said electrical measurement signal comprises a polarizer means for mixing said single output beam orthogonal components.
Claim 95
Dependent Claim
26 words
An angle measuring plane mirror interferometric system in accordance with claim 93 wherein said means for producing said electrical measurement signal further comprises a photoelectric detector.
Claim 96
Dependent Claim
26 words
An angle measuring plane mirror interferometric system in accordance with claim 16 wherein said means for producing said electrical measurement signal further comprises a photoelectric detector.
Claim 97
Dependent Claim
34 words
An angle measuring plane mirror interferometric system in accordance with claim 95 wherein said means for producing said electrical measurement signal further comprises a polarizer means for mixing said single output beam orthogonal components.
Claim 98
Dependent Claim
38 words
An angle measuring plane mirror interferometric system in accordance with claim 79 wherein said means for converting said two separated parallel orthogonally polarized beams into said two same polarized separated parallel beams comprises a half-wave retardation plate means.
Claim 99
Dependent Claim
38 words
An angle measuring plane mirror interferometric system in accordance with claim 83 wherein said means for converting said two separated parallel orthogonally polarized beams into said two same polarized separated parallel beams comprises a half-wave retardation plate means.
Claim 100
Dependent Claim
50 words
An angle measuring plane mirror interferometric system in accordance with claim 79 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors comprises a polarizing beam splitter means and a retroreflector means.
Claim 101
Dependent Claim
47 words
An angle measuring plane mirror interferometric system in accordance with claim 99 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors further comprises a quarter-wave retardation plate means.
Claim 102
Dependent Claim
40 words
An angle measuring plane mirror interferometric system in accordance with claim 100 wherein said means for converting said two separated parallel same polarized output beams into said two separated parallel orthogonally polarized output beams comprises a half-wave retardation plate means.
Claim 103
Dependent Claim
33 words
An angle measuring plane mirror interferometric system in accordance with claim 101 wherein said means for producing said electrical measurement signal comprises a polarized means for mixing said single output beam orthogonal components.
Claim 104
Dependent Claim
50 words
An angle measuring plane mirror interferometric system in accordance with claim 83 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors comprises a polarizing beam splitter means in a retroreflector means.
Claim 105
Dependent Claim
47 words
An angle measuring plane mirror interferometric system in accordance with claim 100 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors further comprises a quarter-wave retardation plate means.
Claim 106
Dependent Claim
40 words
An angle measuring plane mirror interferometric system in accordance with claim 104 wherein said means for converting said two separated parallel same polarized output beams into said two separated parallel orthogonally polarized output beams comprises a half-wave retardation plate means.
Claim 107
Dependent Claim
33 words
An angle measuring plane mirror interferometric system in accordance with claim 105 wherein said means for producing said electrical measurement signal comprises a polarizer means for mixing said single output beam orthogonaly components.
Claim 108
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 1 wherein said source means comprises a laser.
Claim 109
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 16 wherein said source means comprises a laser.
Claim 110
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 1 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 111
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 109 wherein said source means comprises a laser.
Claim 112
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 16 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 113
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 111 wherein said source means comprises a laser.
Claim 114
Dependent Claim
22 words
An angle measuring plane mirror interferometric system in accordance with claim 1 wherein all of said beams are in a single plane.
Claim 115
Dependent Claim
31 words
An angle measuring plane mirror interferometric system in accordance with claim 113 wherein all of said beams are optical beams and all of said optical beams are in a single plane.
Claim 116
Dependent Claim
22 words
An angle measuring plane mirror interferometric system in accordance with claim 16 wherein all of said beams are in a single plane.
Claim 117
Dependent Claim
31 words
An angle measuring plane mirror interferometric system in accordance with claim 115 wherein all of said beams are optical beams and all of said optical beams are in a single plane.
Claim 118
Dependent Claim
88 words
An angle measuring plane mirror interferometric system in accordance with claim 77 wherein said beamsplitter/beam folder assembliy means comprises a first set of regions of antireflection and polarizing coatings, said means for converting said two separated parallel orthogonally polarized output beams into said single output beam comprising said beamsplitter/beam folder assembly means first set of regions and coatings, said beamsplitter/beam folder assembly means further comprising a second set of regions of antireflection and polarizing coatings, said second set of regions and coatings comprising said input beam converting means.
Claim 119
Dependent Claim
64 words
An angle measuring plane mirror interferometric system in accordance with claim 117 wherein said first and second regions of polarizing coatings comprise different portions of a common polarizing coating, said beamsplitter/beam folder assembly means comprising a common beamsplitter/beam folder assembly means comprising a common beamsplitter/beam folder assembly for converting said input beam and said output beam in said angle measuring plane mirror interferometric system.
Claim 120
Dependent Claim
39 words
An angle measuring plane mirror interferometric system in accordance with claim 118 wherein said common beamsplitter/beam folder assembly comprises beam entrance and exit surfaces, said first and second regions of antireflection coatings being on said entrance and exit surfaces.
Claim 121
Dependent Claim
27 words
An angle measuring plane mirror interferometric system in accordance with claim 119 wherein said beamsplitter/beam folder assembly means comprises a right angle prism and a rhomboid prism.
Claim 122
Dependent Claim
50 words
An angle measuring plane mirror interferometric system in accordance with claim 117 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors comprises a polarizing beam splitter means and a retroreflector means.
Claim 123
Dependent Claim
47 words
An angle measuring plane mirror interferometric system in accordance with claim 121 wherein said means for causing each of said separated parallel same polarized beams to be reflected once by each one of said pair of angularly variable plane mirrors further comprises a quarter-wave retardation plate means.
Claim 124
Dependent Claim
40 words
An angle measuring plane mirror interferometric system in accordance with claim 122 wherein said means for converting said two separated parallel same polarized output beams into said two separated parallel orthogonally polarized output beams comprises a half-wave retardation plate means.
Claim 125
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 117 wherein said source means comprises a laser.
Claim 126
Dependent Claim
51 words
An angle measuring plane mirror interferometric system in accordance with claim 117 wherein one of said pair of plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said angle distance between said pair of angularly variable plane mirrors.
Claim 127
Dependent Claim
39 words
An angle measuring plane mirror interferometric system in accordance with claim 117 wherein all of said beams are optical beams, said optical beams being in a plurality of planes, with a given optical beam being in a given plane.
Claim 128
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 126 wherein said source means comprises a laser.
Claim 129
Dependent Claim
84 words
An angle measuring plane mirror interferometric system in accordance with claim 78 wherein said beamsplitter/beam folder assembly means comprises for providing said pair of orthogonally polarized frequency components with said phase difference "δ" in accordance with the expression ##EQU15## wherein "h" is the thickness of the rhomboid prism, "n" is the refractive index of the rhomboid prism, "λ" is the wavelength of said input beam source means, and "θ" is the angular tilt of said pair of plane mirrors with respect to each other.
Claim 130
Dependent Claim
39 words
An angle measuring plane mirror interferometric system in accordance with claim 128 wherein said angular change "Δθ" for small variations in said angular tilt is defined by the expression ##EQU16## where "Δδ" is the variation in said phase difference.
Claim 131
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 129 wherein said source means comprises a laser.
Claim 132
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 130 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 133
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 128 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 134
Dependent Claim
19 words
An angle measuring plane mirror interferometric system in accordance with claim 129 wherein said source means comprises a laser.
Claim 135
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 133 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 136
Dependent Claim
53 words
An angle measuring plane mirror interferometric system in accordance with claim 129 wherein one of said pair of angularly variable plane mirrors is fixed and comprises a reference mirror and the other of said pair of plane mirrors is tiltable for providing said variable angle between said pair of angularly variable plane mirrors.
Claim 137
Dependent Claim
88 words
An angle measuring plane mirror interferometric system in accordance with claim 81 wherein said beamsplitter/beam folder assembly means comprises a first set of regions of antireflection and polarizing coatings, said means for converting said two separated parallel orthogonally polarized output beams into said single output beam comprising said beamsplitter/beam folder assembly means first set of regions and coatings, said beamsplitter/beam folder assembly means further comprising a second set of regions of antireflection and polarizing coatings, said second set of regions and coatings comprising said input beam converting means.
Claim 138
Dependent Claim
57 words
An angle measuring plane mirror interferometric system in accordance with claim 136 wherein said first and second regions of polarizing coatings comprise different portions of a common polarizing coating, said beamsplitter/beam folder assembly means comprising a common beamsplitter/beam folder assembly for converting said input beam and said output beam in said angle measuring plane mirror interferometric system.
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) | 1991-05-24 | 1991-11-23 | 1992-05-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-05-24 | 1995-11-23 | 1996-05-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-05-24 | 1999-11-23 | 2000-05-24 | $7700.00 | Window Closed / Lapsed |