Polarization interferometer spectrometer

Claim 2

A polarization interferometer comprising: a source of light for emitting a beam of light; collimator means receiving said beam of light and converting said beam of light into a beam of parallel rays directed along an optical axis; first polarizing means for polarizing said beam of parallel rays; a double-refractive element including at least two plane-parallel lateral surfaces arranged perpendicularly to the polarized beam of parallel rays, said double refractive element including two optical wedge means each having a wedge surface and coinciding optical axes, said wedge surfaces facing each other to complement one another to a parallelepiped, said wedge means being displaceable relatively to each other along said wedge surfaces; a double refracting plane-parallel plate forming an optical compensator, the optical axis between said compensator and said wedge means being twisted within a plane perpendicular to said beam of light; second polarizing means for polarizing said polarized beam of parallel rays emitted by said double-refractive element along its optical axis; photon detector means receiving said polarized beam of parallel rays emitted by said second polarized means, the optical axes of said first and second polarizing means being arranged non-parallel to the optical axes of said wedge means, while forming an angle with each other having a value which is divisible evenly by 90°; electronic amplifying means connected to said photon detector means to provide an amplified output signal; analog/digital converting means connected to said amplifying means for converting said output signal into a discrete numerical interferogram; digital filter means for filtering said numerical interferogram; electronic means connected to said digital filter means for carrying out a Fourier Transformation of the filtered numerical interferogram; and spectrogram forming means connected to said electronic means for representing said filtered numerical interferogram after Fourier Transformation as a spectrogram.

Claim 3

A polarization interferometer as claimed in claim 1, wherein the optical axes of said first and said second polarizing means are perpendicular to each other.

Claim 4

A polarization interferometer as claimed in claim 1, wherein the optical axes of said first and said second polarizing means are parallel to each other.

Claim 5

A polarization interferometer as claimed in claim 1, wherein said first and said second polarizing means linearly polarize said beam of light.

Claim 6

A polarization interferometer as claimed in claim 1, wherein the optical axes of each of said polarizing means form an angle of 45 degrees to the axes of said wedge means.

Claim 7

A polarization interferometer as claimed in claim 1, further comprising: a monochromatic light source emitting a beam of monochromatic light; and means for coupling said monochromatic beam of light with said beam of parallel rays, said coupling means including first beam splitting means located behind said second polarizing means so that said beam of parallel rays and said beam of monochromatic light have opposite directions, and second beam splitting means arranged before said first polarizing means, when seen in the direction of said beam of monochromatic light, for deviating the beam toward said photon detector means.

Claim 8

A polarization interferometer as claimed in claim 6, further comprising optical band-pass filter means arranged before said photon detector means for allowing only said beam of monochromatic light to pass through.

Claim 9

A polarization interferometer as claimed in claim 1, further comprising: a monochromatic light source emitting a beam of monochromatic light; second photon detector means; first beam splitting means for coupling said beam of monochromatic light into said beam of parallel rays, said first beam splitting means being located between said second polarizing means and said first-mentioned detector means; and second beam splitting means located between said first polarizing means and said first-mentioned light source for deviating said beam of monochromatic light onto said second photon detector means.

Claim 10

A polarization interferometer as claimed in claim 8, further comprising optical band-pass filter means arranged before said second photon detector means for allowing only said beam of monochromatic light to pass through.

Claim 11

A polarization interferometer as claimed in claim 1, further comprising: a monochromatic light source emitting a beam of monochromatic light along an optical axis separated from the optical axis of said beam of parallel rays; second photon detector means; first beam splitting means for dividing said beam of monochromatic light into a first beam and a second beam; first mirror means for coupling said first beam of monochromatic light into said beam of parallel rays, said mirror means being arranged between said first polarizing means and said compensator; second beam splitting means arranged between said double-refractive element and said second polarizing means so as to provide a deviated optical axis directed toward said second photon detector means; second mirror means arranged to deviate said second beam toward said second beam splitting means so that said first and said second beams meet again and are thereby directed towards said second photon detector means.

Claim 12

A polarization interferometer as claimed in claim 1, wherein one of said optical wedge means is movable relative to a second of said optical wedge means, said polarization interferometer further comprising means forming a Michelson interferometer means, said Michelson interferometer means including a movable reflective surface arranged on said movable one of said wedge means.

Claim 13

A polarization interferometer as claimed in claim 1, wherein the optical axes of said compensator, as compared to that of said wedge means, is twisted by 90 degrees within a plane perpendicular to said beam of light.

Claim 14

A polarization interferometer as claimed in claim 1, further comprising scale means for measuring the displacement of at least one of said wedge means.

Claim 15

A polarization interferometer as claimed in claim 13, wherein said scale means comprises diffraction grid means for measuring said displacement by using a moire method.

Claim 16

A polarization interferometer as claimed in claim 1, wherein said photon detector means comprises a lead sulphide cell.

Claim 17

A polarization interferometer as claimed in claim 1, wherein said photon detector means comprises a silicon photodiode.

Claim 18

A polarization interferometer as claimed in claim 1, further comprising electronic amplifying means connected to said photon detector means to provide an amplified output signal; and analog/digital converting means connected to said amplifying means for converting said output signal into a discrete numerical interferogram.

Claim 19

A polarization interferometer as claimed in claim 17, further comprising: digital filter means for filtering said numerical interferogram; electronic means connected to said digital filter means for carrying out a Fast Fourier Transformation of the filtered numerical interferogram; and spectrogram forming means connected to said electronic means for representing said filtered numerical interferogram after Fast Fourier Transformation as a spectrogram.

Claim 20

A polarization interferometer as claimed in claim 1, wherein said Fourier Transformation is a Fast Fourier Transformation.

Claim 21

A polarization interferometer comprising: a source of light for emitting a beam of light; collimator means receiving said beam of light and converting said beam of light into a beam of parallel rays directed along a first optical axis; polarizing means for polarizing said beam of parallel rays in a first predetermined polarizing direction, the polarizing means comprising lineraly polarizing beam splitting means for providing a second optical axis forming an angle with said first optical axis; a double-refractive element including at least two plane-parallel lateral surfaces arranged perpendicularly to the polarized beam of parallel rays, said double-refractive element including two optical wedge means each having a wedge surface and coinciding optical axes, said wedge surfaces facing each other to complement one another to a parallelepiped, said wedge means being displaceable relatively to each other along said wedge surfaces, the polarizing direction of said polarizing beam splitting means being non-parallel to the axes of said optical wedge means; a double refracting plane-parallel plate forming an optical compensator, the optical axis between said compensator and said wedge means being twisted within a plane perpendicular to said beam of light, said compensator being located in front of said double-refractive element and between said double-refractive element and said polarizing means; mirror means situated behind said double-refractive element for reflecting said beam of light emitted by the double-refracting element toward said polarizing means for polarizing said beam a second time in a second direction by said polarizing means, said polarizing means thus deviating said rays by said beam splitting means along said second optical axis, said first and said second optical axes forming an angle with each other having a value which is divisible evenly by 90°; and photon detector means receiving said polarized beam of parallel rays emitted by said polarizing means and being arranged in a conjugated plane relatively to said source of light.

Claim 22

A polarization interferometer comprising: a source of light for emitting a beam of light; collimator means receiving said beam of light and converting said beam of light into a beam of parallel rays directed along a first optical axis; polarizing means for polarizing said beam of parallel rays in a first predetermined polarizing direction, the polarizing means comprising lineraly polarizing beam splitting means for providing a second optical axis forming an angle with said first optical axis; a double-refractive element including at least two plane-parallel lateral surfaces arranged perpendicularly to the polarized beam of parallel rays, said double-refractive element including two optical wedge means each having a wedge surface and coinciding optical axes, said wedge surfaces facing each other to complement one another to a parallelepiped, said wedge means being displaceable relatively to each other along said wedge surfaces, the polarizing direction of said polarizing beam splitting means being non-parallel to the axes of said optical wedge means; a double refracting plane-parallel plate forming an optical compensator, the optical axis between said compensator and said wedge means being twisted within a plane perpendicular to said beam of light, said compensator being located in front of said double-refractive element and between said double-refractive element and said polarizing means; mirror means situated behind said double-refractive element for reflecting said beam of light emitted by the double-refracting element toward said polarizing means for polarizing said beam a second time in a second direction by said polarizing means, said polarizing means thus deviating said rays by said beam splitting means along said second optical axis, said first and said second optical axes forming an angle with each other having a value which is divisible evenly by 90°; and photon detector means receiving said polarized beam of parallel rays emitted by said polarizing means and being arranged in a conjugated plane relatively to said source of light.

Claim 23

A polarization interferometer as claimed in claim 20, wherein the optical axes of said polarizing means are perpendicular to each other.

Claim 24

A polarization interferometer as claimed in claim 20, wherein the optical axes of said polarizing means are parallel to each other.

Claim 25

A polarization interferometer as claimed in claim 20, wherein said polarizing means lineraly polarizes said beam of light.

Claim 26

A polarization interferometer as claimed in claim 20, wherein the optical axes of said polarizing means form an angle of 45 degrees to the axes of said wedge means.

Claim 27

A polarization interferometer as claimed in claim 20, further comprising: a monochromatic light source emitting a beam of monochromatic light, and second photon detector means; and means for coupling said monochromatic beam of light with said beam of parallel rays, said coupling means including first beam splitting means located behind said second polarizing means so that said beam of parallel rays and said beam of monochromatic light have opposite directions; and second beam splitting means arranged before said first polarizing means, when seen in the direction of said beam of monochromatic light, for deviating the beam of monochromatic light toward said second photon detector means.

Claim 28

A polarization interferometer as claimed in claim 25, further comprising optical band-pass filter means arranged before said second photon detector means for allowing only said beam of monochromatic light to pass through.

Claim 29

A polarization interferometer as claimed in claim 20, further comprising: a monochromatic light source emitting a beam of monochromatic light, and a second photon detecting means; first beam splitting means for coupling said beam of monochromatic light into said beam of parallel rays, said beam splitting means preceding said first polarizing means; and second beam splitting means arranged behind said second polarizing means for deviating said beam of monochromatic light onto said second photon detector means.

Claim 30

A polarization interferometer as claimed in claim 27, further comprising optical band-pass filter means arranged before said second photon detector means for allowing only said beam of monochromatic light to pass through.

Claim 31

A polarization interferometer as claimed in claim 20, further comprising: a monochromatic light source emitting a beam of monochromatic light along an optical axis separated from the optical axis of said beam of parallel rays; second photon detector means; first beam splitting means for dividing said beam of monochromatic light into a first beam and a second beam; first mirror means for coupling said first beam of monochromatic light into said beam of parallel rays, said first mirror means being arranged between said polarizing means and said compensator; second beam splitting means arranged between said double-refractive element and said first-mentioned photon detector means so as to provide a deviated optical axis directed toward said second photon detector means; second mirror means arranged to deviate said second beam toward said second beam splitting means so that said first and said second beams meet again and are thereby directed towards said second photon detector means.

Claim 32

A polarization interferometer as claimed in claim 20, wherein one of said wedge means is movable relative to a second of said wedge means, the polarization interferometer further comprising means forming a Michelson interferometer, said Michelson interferometer means including a movable reflective surface arranged on said movable one of said wedge means.

Claim 33

A polarization interferometer as claimed in claim 20, wherein the optical axes of said compensator, as compared to that of said wedge means, is twisted by 90 degrees within a plane perpendicular to said beam of light.

Claim 34

A polarization interferometer as claimed in claim 20, wherein said predetermined polarizing direction of said polarizing means forms an angle of 45 degrees to the axes of said wedge means.

Claim 35

A polarization interferometer as claimed in claim 20, further comprising scale means for measuring the displacement of at least one of said wedge means.

Claim 36

A polarization interferometer as claimed in claim 33, wherein said scale means comprise diffraction grid means for measuring said displacement by using a moire method.

Claim 37

A polarization interferometer as claimed in claim 20, wherein said photon detector means comprise a lead sulphide cell.

Claim 38

A polarization interferometer as claimed in claim 20, wherein said photon detector means comprise a silicon photodiode.

Claim 39

A polarization interferometer as claimed in claim 20, further comprising: electronic amplifying means connected to said photon detector means to provide an amplified output signal; and analog/digital converting means connected to said amplifying means for converting said output signal into a discrete numerical interferogram.

Claim 40

A polarization interferometer as claimed in claim 37, further comprising: digital filter means for filtering said numerical interferogram; electronic means connected to said digital filter means for carrying out a Fast Fourier Transformation of the filtered numerical interferogram; and spectrogram forming means connected to said electronic means for representing said filtered numerical interferogram after Fast Fourier Transformation as a spectrogram.

Claim 41

A polarization interferometer comprising: a source of light for emitting a beam of light; collimator means receiving said beam of light and converting it into a beam of parallel rays directed along an optical axis; first polarizing means for polarizing said beam of parallel rays; a double-refractive element including at least two plane-parallel lateral surfaces disposed perpendicularly to the polarized beam of parallel rays, said double refractive element including two optical wedge means each having a wedge surface and an optical axis, the optical axes coinciding in a common axis, said wedge surfaces facing each other to complement one another to a parallelepiped, said wedge means being displaceable relatively to each other along said wedge surfaces; an optical compensator comprising a double refracting plane-parallel plate located along a path of said beam in front of said wedge means, an optical axis between said compensator and said wedge means being twisted within a plane perpendicular to said beam of light; second polarizing means operative for polarizing the beam emitted by said double-refractive element along its optical axis; photon detector means receiving the beam emitted by said double-refractive element subsequent to polarization by said second polarizing means; electronic amplifying means connected to said photon detector means to provide an amplified output signal; analog/digital converting means connected to said amplifying means for converting said output signal into a discrete numerical interferogram; digital filter means for filtering said numerical interferogram; electronic means connected to said digital filter means for carrying out a Fourier Transformation of the filtered numerical interferogram; spectrogram forming means connected to said electronic means for representing said filtered numerical interferogram after Fourier Transformation as a spectrogram; and said first polarizing means has at least one optical axis angled in nonparallel relation to said common axis of said wedge means.

Claim 42

A polarization interferometer comprising: a source of light for emitting a beam of light; collimator means receiving said beam of light and converting it into a beam of parallel rays directed along an optical axis; first polarizing means for polarizing said beam of parallel rays; a double-refractive element including at least two plane-parallel lateral surfaces disposed perpendicularly to the polarized beam of parallel rays, said double refractive element including two optical wedge means each having a wedge surface and an optical axis, the optical axes coinciding in a common axis, said wedge surfaces facing each other to complement one another to a parallelepiped, said wedge means being displaceable relatively to each other along said wedge surfaces; an optical compensator comprising a double refracting plane-parallel plate located along a path of said beam in front of said wedge means, an optical axis between said compensator and said wedge means being twisted within a plane perpendicular to said beam of light; second polarizing means operative for polarizing the beam emitted by said double-refractive element along its optical axis; photon detector means receiving the beam emitted by said double-refractive element subsequent to polarization by said second polarizing means; electronic amplifying means connected to said photon detector means to provide an amplified output signal; analog/digital converting means connected to said amplifying means for converting said output signal into a discrete numerical interferogram; digital filter means for filtering said numerical interferogram; electronic means connected to said digital filter means for carrying out a Fourier Transformation of the filtered numerical interferogram; spectrogram forming means connected to said electronic means for representing said filtered numerical interferogram after Fourier Transformation as a spectrogram; and said first polarizing means has at least one optical axis angled in nonparallel relation to said common axis of said wedge means.

Claim 43

A polarization interferometer as claimed in claim 38, wherein said polarizing means has two optical axes, and said polarization interferometer further comprises a mirror for reflecting an optical path back through said second polarizing means and said wedges, said two optical axes of said second polarizing means being perpendicular to each other.

Claim 44

A polarization interferometer as claimed in claim 39, wherein said first polarizing means has two optical axes which are parallel to each other.

Claim 45

A polarization interferometer as claimed in claim 39, wherein said first polarizing means linearly polarizes said beam of light.

Claim 46

A polarization interferometer as claimed in claim 39, wherein an optical axis of said first polarizing means forms an angle of 45 degrees to the common axis of said wedge means.

Claim 47

A polarization interferometer comprising: a source of light for emitting a beam of light; collimator means receiving said beam of light and converting said beam of light into a beam of parallel rays directed along an optical axis; first polarizing means for polarizing said beam of parallel rays; a double-refractive element including at least two plane-parallel lateral surfaces arranged perpendicularly to the polarized beam of parallel rays, said double refractive element including two optical wedge means each having a wedge surface and coinciding optical axes, said wedge surfaces facing each other to complement one another to a parallelepiped, said wedge means being displaceable relatively to each other along said wedge surfaces; a double refracting plane-parallel plate forming an optical compensator, the optical axis between said compensator and said wedge means being twisted within a plane perpendicular to said beam of light; second polarizing means for polarizing said polarized beam of parallel rays emitted by said double-refractive element along its optical axis; and photon detector means receiving said polarized beam of parallel rays emitted by said second polarizing means, the optical axes of said first and second polarizing means being arranged non-parallel to the optical axes of said wedge means, while forming an angle with each other having a value which is divisible evenly by 90°.

Claim 48

A polarization interferometer comprising: a source of light for emitting a beam of light; collimator means receiving said beam of light and converting said beam of light into a beam of parallel rays directed along an optical axis; first polarizing means for polarizing said beam of parallel rays; a double-refractive element including at least two plane-parallel lateral surfaces arranged perpendicularly to the polarized beam of parallel rays, said double refractive element including two optical wedge means each having a wedge surface and coinciding optical axes, said wedge surfaces facing each other to complement one another to a parallelepiped, said wedge means being displaceable relatively to each other along said wedge surfaces; a double refracting plane-parallel plate forming an optical compensator, the optical axis between said compensator and said wedge means being twisted within a plane perpendicular to said beam of light; second polarizing means for polarizing said polarized beam of parallel rays emitted by said double-refractive element along its optical axis; and photon detector means receiving said polarized beam of parallel rays emitted by said second polarizing means, the optical axes of said first and second polarizing means being arranged non-parallel to the optical axes of said wedge means, while forming an angle with each other having a value which is divisible evenly by 90°.