TY - JOUR
T1 - 3D surface profile measurement of unsymmetrical microstructure using Fizeau interferometric microscope
AU - Yang, Shih Wei
AU - Lin, Chern Sheng
AU - Lin, Shir-Kuan
PY - 2013/4/1
Y1 - 2013/4/1
N2 - In this paper, an automatic optical inspection system for the 3D surface profile of an unsymmetrical microstructure using Fizeau interferometer was proposed. This non-contact optical inspection system is suitable for measuring the lens sag and 3D surface profile of symmetrical and unsymmetrical microlenses. Referring to the unsymmetrical microlenses as an example, the distribution of the interference fringes is partly dense and partly rare, and is completely different from the equally dense distribution of symmetrical microlenses. Thus, a novel algorithm is proposed to solve the above mentioned problem in this paper, namely, individually determining the darkest points of the dark fringes and the brightest points of the bright fringes, and fitting these discrete points as close curves through the Bezier curve theory. As the contour lines of an unsymmetrical microlens are obtained, the 3D surface profile of the unsymmetrical microlens can be plotted correspondingly. Furthermore, the proposed system has the following advantages due to its non-contact structure. This system is specifically designed for in-line measurements according to the rapid inspection speed; it has no need to coat a reflective layer on the inspected microstructure, thus avoiding damaging the surface structure of the sample.
AB - In this paper, an automatic optical inspection system for the 3D surface profile of an unsymmetrical microstructure using Fizeau interferometer was proposed. This non-contact optical inspection system is suitable for measuring the lens sag and 3D surface profile of symmetrical and unsymmetrical microlenses. Referring to the unsymmetrical microlenses as an example, the distribution of the interference fringes is partly dense and partly rare, and is completely different from the equally dense distribution of symmetrical microlenses. Thus, a novel algorithm is proposed to solve the above mentioned problem in this paper, namely, individually determining the darkest points of the dark fringes and the brightest points of the bright fringes, and fitting these discrete points as close curves through the Bezier curve theory. As the contour lines of an unsymmetrical microlens are obtained, the 3D surface profile of the unsymmetrical microlens can be plotted correspondingly. Furthermore, the proposed system has the following advantages due to its non-contact structure. This system is specifically designed for in-line measurements according to the rapid inspection speed; it has no need to coat a reflective layer on the inspected microstructure, thus avoiding damaging the surface structure of the sample.
KW - 3D surface profile
KW - Bezier curve
KW - Fizeau interferometer
KW - Unsymmetrical microstructure
UR - http://www.scopus.com/inward/record.url?scp=84872902663&partnerID=8YFLogxK
U2 - 10.1016/j.optlaseng.2012.12.004
DO - 10.1016/j.optlaseng.2012.12.004
M3 - Article
AN - SCOPUS:84872902663
VL - 51
SP - 348
EP - 357
JO - Optics and Lasers in Engineering
JF - Optics and Lasers in Engineering
SN - 0143-8166
IS - 4
ER -