Fraunhofer-Gesellschaft

Publica

Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

Digital holography on moving objects. Multiwavelength height measurements on inclined surfaces

 
: Schiller, Annelie; Beckmann, Tobias; Fratz, Markus; Belzer, Dominik; Bertz, Alexander; Carl, Daniel; Buse, Karsten

:
Fulltext urn:nbn:de:0011-n-4613485 (4.4 MByte PDF)
MD5 Fingerprint: 0166d978cd3c517ad07fed052dbb8c17
Created on: 9.8.2017


Lehmann, Peter H. (Ed.) ; Society of Photo-Optical Instrumentation Engineers -SPIE-, Bellingham/Wash.:
Optical Measurement Systems for Industrial Inspection X : Munich, Germany; 25 June 2017
Bellingham, WA: SPIE, 2017 (Proceedings of SPIE 10329)
ISBN: 978-1-5106-1103-0
Paper 103290D, 7 pp.
Conference "Optical Measurement Systems for Industrial Inspection" <10, 2017, Munich>
English
Conference Paper, Electronic Publication
Fraunhofer IPM ()
digital holography

Abstract
Multiwavelength digital holography on moving objects enables fast and precise inline-measurements of surface pro files. Due to the use of multiple wavelengths, optically rough surfaces with structure heights in the micrometer range can be mapped unambiguously. In this work we explore the influence of the object velocity on height measurements on inclined surfaces. We show measurements using spatial-phase-shifting holography employing two wavelengths and object velocities of up to 90 mm/s with eye-safe cw-lasers with less than 1 mW of laser light. Despite motion blur exceeding the mean speckle size, reliable height measurements can be conducted at these velocities. The height map of a metal cone with two different slope angles (1° , 10° ) is measured at an exposure time of 2 ms. Using line shaped illumination, each frame yields a height map of approximately 2 x 17 mm2. The overlap between the frames allows averaging as the image is put together, improving data quality. The mean repeatability of the height information in the investigated setup is better than 4.5 µm at a synthetic wavelength of 214 µm.

: http://publica.fraunhofer.de/documents/N-461348.html