Arrangement for optical autocorrelation
First Claim
1. An arrangement for optical autocorrelation of film recordings of laser speckle photography or particle image velocimetry with a laser light source comprising:
- a laser light source having light which penetrates a laser speckle photographic or particle image velocimetry recording so that Young'"'"'s fringe patterns occur in the image-side focal plane of a Fourier transform objective;
an optically addressable liquid crystal SLM on which the fringe pattern is imaged;
a second laser light source which reads out the liquid crystal SLM and, by a second Fourier transform objective, produces a diffraction pattern corresponding to the Fourier-transformed Young'"'"'s fringes;
a camera for recording the diffraction pattern;
said liquid crystal SLM containing a uniaxial double-refracting liquid crystal layer which is read out with linearly polarized light of the second laser light source on the readout side; and
wherein the polarization direction of said second laser light source coincides with the extraordinary semi-axis of the refractive index ellipsoid of said liquid crystal layer.
1 Assignment
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Accused Products
Abstract
An arrangement for optical autocorrelation of laser speckle photography (LSP) photographs or particle image velocimetry (PIV) photographs using optical Fourier transforms is disclosed. The object of providing an electro-optical arrangement for optical correlation of LSP film recordings and PIV film recordings which is simple to produce and accurate is met by using an optically addressable liquid crystal SLM (spatial light modulator) for producing the Young'"'"'s fringe patterns which contains a uniaxial double-refracting liquid crystal layer and is read out with linearly polarized light of a laser light source, wherein the polarization direction of the laser light source on the readout side coincides with the extraordinary semi-axis of the refractive index ellipsoid of the liquid crystal layer.
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Citations
7 Claims
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1. An arrangement for optical autocorrelation of film recordings of laser speckle photography or particle image velocimetry with a laser light source comprising:
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a laser light source having light which penetrates a laser speckle photographic or particle image velocimetry recording so that Young'"'"'s fringe patterns occur in the image-side focal plane of a Fourier transform objective; an optically addressable liquid crystal SLM on which the fringe pattern is imaged; a second laser light source which reads out the liquid crystal SLM and, by a second Fourier transform objective, produces a diffraction pattern corresponding to the Fourier-transformed Young'"'"'s fringes; a camera for recording the diffraction pattern; said liquid crystal SLM containing a uniaxial double-refracting liquid crystal layer which is read out with linearly polarized light of the second laser light source on the readout side; and wherein the polarization direction of said second laser light source coincides with the extraordinary semi-axis of the refractive index ellipsoid of said liquid crystal layer. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification