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Olomouc 2017 Light interferometry Pavel Pavlíček
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Welcome speech
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Welcome speech
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Light interferometry Interferometry : technique Interference : phenomenon
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Interferometry : technique
Interference : phenomenon crest cresta hřeben trough ventre brázda
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Interference is a phenomenon in which two waves superpose
anatomy of a wave crest cresta hřeben trough ventre brázda
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Superposition of waves
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Superposition of waves
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Superposition of waves
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Superposition of waves
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Superposition of waves
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Superposition of waves
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Superposition of waves
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Superposition of waves
in phase
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Superposition of waves
in phase
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Superposition of waves
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Superposition of waves
out of phase
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Superposition of waves
out of phase
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Interference continuum of possibilities between „in phase“ and „out of phase“ out of phase in phase wave of zero amplitude giant wave constructive interference destructive interference
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Interference
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waves are superimposed => information about the waves
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Michelson interferometer (1880s)
Light source Detector
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Michelson interferometer
Light source in phase I ~10-4 nm Detector l
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Michelson interferometer
Light source l/4 out of phase Detector
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Michelson interferometer
Light source l/2 in phase Detector l/4 l/2 (3/4)l l
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Classical interferometry
How does it work? CCD l/4 l/2 light source measured object
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How does it work? CCD l/4 l/2 light source measured object
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Michelson-type interferogram
phase the deviation of the measured surface from the reference plane y x
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A problem: ambiguity
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Michelson interferometer
Light source I in phase ~ nm Detector l
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Michelson interferometer
Light source l/4 I out of phase ~ nm Detector l
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Michelson interferometer
Light source l/2 in phase Detector l/4 l/2 (3/4)l l
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Spectra and interferograms of various sources
~10-4 nm z l I I ~ nm l z I I ~ 1200 nm l z
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Measured interferogram of He-Ne laser (l = 633 nm)
45 mm
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Measured interferogram of He-Ne laser (l = 633 nm)
45 mm
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Measured interferogram of He-Ne laser (l = 633 nm)
45 mm
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Measured interferogram of a LED (diodo ad emissione luminosa)
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Measured interferogram of a LED (diodo ad emissione luminosa)
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Measured interferogram of a LED (diodo ad emissione luminosa)
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Measured interferogram of an incandescent lamp
(lampadina) intensity path difference
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White-light interferometry
How does it work? CCD light source measured object reference mirror
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How does it work? CCD light source measured object reference mirror
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How does it work? CCD light source measured object reference mirror
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How does it work? CCD light source measured object reference mirror
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Measured height profile
height profile coded by gray scales cross section along the horizontal line 100 mm
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Measured interferogram and its envelope
74.7 mm 111.9 mm
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Thank you for your attention
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