Absolute and relative surface profile interferometry using multiple frequency-scanned lasers

0469283 - ÚFP 2017 RIV US eng C - Conference Paper (international conference)
Peca, M. - Psota, Pavel - Vojtíšek, Petr - Lédl, Vít
Absolute and relative surface profile interferometry using multiple frequency-scanned lasers.
Proceedings of SPIE 10151, Optics and Measurement International Conference 2016. Vol. 10151. Bellingham: SPIE, Society of Photo-Optical Instrumentation Engineers, 2016 - (Kovačičinová, J.), č. článku 101510H. SPIE. ISBN 978-1-5106-0753-8. ISSN 0277-786X.
[OAM 2016, Optics and Measurement International Conference 2016. Liberec (CZ), 11.10.2016-14.10.2016]
R&D Projects: GA TA ČR(CZ) TA03010893
Institutional support: RVO:61389021
Keywords : Absolute interferometry * diode laser * surface prole * length measurement
Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering
http://dx.doi.org/10.1117/12.2263656

An interferometer has been used to measure the surface prole of generic object. Frequency scanning interferometryhas been employed to provide unambiguous phase readings, to suppress etalon fringes, and to supersede phase-shifting. The frequency scan has been performed in three narrow wavelength bands, each generated by a temperature tuned laser diode. It is shown, that for certain portions of measured object, it was possible to get absolute phase measurement, counting all wave periods from the point of zero path dierence, yielding precision of 2.7nm RMS over 11.75mm total path dierence. For the other areas where steep slopes were present in object geometry, a relative measurement is still possible, at measured surface roughness comparable to that of machining process (the same 2.7nm RMS). It is concluded, that areas containing steep slopes exhibit systematic error, attributed to a combined factors of dispersion and retrace error.
Permanent Link: http://hdl.handle.net/11104/0267095