High-precision white light interferometry based on a color CCD and peak matching algorithm

• Published in: Journal of the Korean Physical Society Vol. 80; no. 7; pp. 599 - 605
• Main Authors: Im, Jaeseung, Kim, Hyuntae, Park, Woongkyu, Ahn, Jae Sung, Lee, Byeongil, Choi, Soobong
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Physical Society 01.04.2022; Springer Nature B.V; 한국물리학회
• Subjects: Algorithms; Charge coupled devices; Color matching; Errors; Interferometry; Mathematical and Computational Physics; Original Paper - Condensed Matter; Particle and Nuclear Physics; Physics; Physics and Astronomy; Theoretical; Topography; White light interferometry; 물리학; Peak matching algorithm; Color CCD camera; White light interferometry; Topography
• ISSN: 0374-4884; 1976-8524
• DOI: 10.1007/s40042-022-00421-1

White light interferometry (WLI) is a widely used technique in various research fields because it can quickly measure the topography of a sample over a large area. In conventional WLI, the topography of the sample is generally obtained by using the envelope of the interferogram. However, this method cannot determine the precise order of the fringes because it is very sensitive to longitudinal chromatic aberration which may cause several measurement errors. Here, we propose an algorithm for avoiding errors in the measurement of the sample’s topography. The concept of the peak matching algorithm and the development of a new scheme of acquiring the topography of the sample by using a color charge-coupled device (CCD) is proposed. We demonstrate that our method can reject the fringe distortion problem encountered when using a conventional WLI system to measure the discrete sample surface. We expect our method to be applied to a variety of research and in industrial fields that require precise topographic measurements.