Open AccessTilt metrology on rough dielectric surfaces using low coherence scanning interferometry
Author(s) -
Chang-Yun Lee,
Jong-Bum You,
Yunseok Kim
Publication year - 2019
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.27.035981
Subject(s) - optics , tilt (camera) , metrology , materials science , interferometry , profilometer , white light interferometry , coherence (philosophical gambling strategy) , surface roughness , tilt sensor , physics , optical fiber , mechanical engineering , quantum mechanics , engineering , composite material
In this investigation, we propose a technique to obtain not only the dimensional surface profile but also tilt information of the rough dielectric surface having a few microns root-mean-square roughness. This technique is based on low coherence scanning interferometry (LCSI) using a compound light source by combining a superluminescent light-emitting diode with ytterbium-doped fiber amplifier. Tilt angle and direction of the measured surface is extracted by the principal component analysis (PCA) from the measurement surface data and the centroid peak detection algorithm. To verify the performance of the proposed tilt measurement method, standard angle gauge block and certified step height sample were used as specimens. LCSI tilt measurement was about 3 times superior to the conventional auto-collimator in terms of the measurement precision in the practical camera module manufacturing process of smartphones. The proposed method was also discussed the dynamic tilt evaluation for the moving object.