Combined Reduced Phase Dual-Directional Illumination Digital Holography and Speckle Displacements for Shape Measurement

We present a digital holographic method to increase height range measurement with a reduced phase ambiguity using a dual-directional illumination. Small changes in the angle of incident illumination introduce phase differences between the recorded complex fields. We decrease relative phase differenc...

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Main Author: Davood Khodadad
Format: Article
Language:English
Published: Wiley 2019-01-01
Series:International Journal of Optics
Online Access:http://dx.doi.org/10.1155/2019/4906109
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author Davood Khodadad
author_facet Davood Khodadad
author_sort Davood Khodadad
collection DOAJ
description We present a digital holographic method to increase height range measurement with a reduced phase ambiguity using a dual-directional illumination. Small changes in the angle of incident illumination introduce phase differences between the recorded complex fields. We decrease relative phase difference between the recorded complex fields 279 and 139 times by changing the angle of incident 0.5° and 1°, respectively. A two cent Euro coin edge groove is used to measure the shape. The groove depth is measured as ≈300  μm. Further, numerical refocusing and analysis of speckle displacements in two different planes are used to measure the depth without a use of phase unwrapping process.
format Article
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institution Kabale University
issn 1687-9384
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language English
publishDate 2019-01-01
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record_format Article
series International Journal of Optics
spelling doaj-art-96769d83a6a54929a30d26e9c35cbff02025-08-20T03:37:30ZengWileyInternational Journal of Optics1687-93841687-93922019-01-01201910.1155/2019/49061094906109Combined Reduced Phase Dual-Directional Illumination Digital Holography and Speckle Displacements for Shape MeasurementDavood Khodadad0Department of Mechanical Engineering, Örebro University, SE-701 82 Örebro, SwedenWe present a digital holographic method to increase height range measurement with a reduced phase ambiguity using a dual-directional illumination. Small changes in the angle of incident illumination introduce phase differences between the recorded complex fields. We decrease relative phase difference between the recorded complex fields 279 and 139 times by changing the angle of incident 0.5° and 1°, respectively. A two cent Euro coin edge groove is used to measure the shape. The groove depth is measured as ≈300  μm. Further, numerical refocusing and analysis of speckle displacements in two different planes are used to measure the depth without a use of phase unwrapping process.http://dx.doi.org/10.1155/2019/4906109
spellingShingle Davood Khodadad
Combined Reduced Phase Dual-Directional Illumination Digital Holography and Speckle Displacements for Shape Measurement
International Journal of Optics
title Combined Reduced Phase Dual-Directional Illumination Digital Holography and Speckle Displacements for Shape Measurement
title_full Combined Reduced Phase Dual-Directional Illumination Digital Holography and Speckle Displacements for Shape Measurement
title_fullStr Combined Reduced Phase Dual-Directional Illumination Digital Holography and Speckle Displacements for Shape Measurement
title_full_unstemmed Combined Reduced Phase Dual-Directional Illumination Digital Holography and Speckle Displacements for Shape Measurement
title_short Combined Reduced Phase Dual-Directional Illumination Digital Holography and Speckle Displacements for Shape Measurement
title_sort combined reduced phase dual directional illumination digital holography and speckle displacements for shape measurement
url http://dx.doi.org/10.1155/2019/4906109
work_keys_str_mv AT davoodkhodadad combinedreducedphasedualdirectionalilluminationdigitalholographyandspeckledisplacementsforshapemeasurement