Shape reconstruction using dual wavelength digital holography and speckle movements
2013 (English)In: Optical Measurement Systems for Industrial Inspection VIII, / [ed] Peter H. Lehmann; Wolfgang Osten; Armando Albertazzi, SPIE - International Society for Optical Engineering, 2013Conference paper (Refereed)
A new technique to measure depth based on dual wavelength digital holography and image correlation of speckle movements is demonstrated. By numerical refocusing of the complex optical field to different focus planes and by measuring the speckle movements caused by a wavelength shift both the object surface position and its local slope can be determined. It is shown how the speckle movement varies linearly with the surface slope, the wavelength shift and the distance of the numerical propagation. This gives a possibility to measure the slope with approximately the same precision as from the interferometric phase maps. In addition, when the object surface is in focus there is no speckle movement so by estimating in what plane the speckle movement is zero the absolute surface position can be measured.
Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2013.
Proceedings of S P I E - International Society for Optical Engineering, ISSN 0277-786X ; 8788
Research subject Experimental Mechanics
IdentifiersURN: urn:nbn:se:ltu:diva-39878DOI: 10.1117/12.2020471Local ID: ecbd8f00-95cd-4b67-9fe7-51df416da530ISBN: 978-0-8194-9604-1OAI: oai:DiVA.org:ltu-39878DiVA: diva2:1013397
Optical Measurement Systems for Industrial Inspection : 13/05/2013 - 13/05/2013
Validerad; 2013; Bibliografisk uppgift: Article number 87880I; 20130814 (ysko)2016-10-032016-10-032017-01-19Bibliographically approved