Optical coherence tomography (OCT) is a powerful optical method, noninvasive and noncontact diagnostic method. Although it is usually used for medical examinations, particularly in ocular exploration; it can also be used in optical metrology as measure technique. In this work, we use OCT to measure thicknesses of films. In OCT, depth profiles are constructed by measuring the time delay of back reflected light by interferometry measurements. Frequency in k-space is proportional to optical path difference. Then the reflectivity profile is obtained by a Fourier transformation, and the difference between two successive peaks of the resulting spectrum gives the film thickness. Several films, food-type, of different thicknesses were investigated and the results were very accurate.

Date Published: 6 January 2015
PDF: 5 pages
Proc. SPIE 9450, Photonics, Devices, and Systems VI, 945006 (6 January 2015); doi: 10.1117/12.2061387

Published in SPIE Proceedings Vol. 9450:
Photonics, Devices, and Systems VI
Pavel Tománek; Dagmar Senderáková; Petr Páta, Editor(s)