White light single-shot interferometry with colour CCD camera for optical inspection of microsystems
Upputuri, Paul Kumar
Nandigana, Krishna Mohan
Date of Issue2015
International Conference on Optical and Photonic Engineering (icOPEN 2015)
School of Chemical and Biomedical Engineering
White light interferometry is a well-established optical tool for surface metrology of reflective samples. In this work, we discuss a single-shot white light interferometer based on single-chip color CCD camera and Hilbert transformation. The approach makes the measurement dynamic, faster, easier and cost-effective for industrial applications. Here we acquire only one white light interferogram using colour CCD camera and then decompose into its individual components using software. We present a simple Hilbert transformation approach to remove the non-uniform bias associated with the interference signal. The phases at individual wavelengths are calculated using Hilbert transformation. The use of Hilbert transformation introduces phase error which depends on number of fringe cycles. We discuss these errors. Experimental results on reflective micro-scale-samples for surface profiling are presented.
© 2015 [SPIE] This paper was published in [Proceedings SPIE 9524] and is made available as an electronic reprint (preprint) with permission of [SPIE]. The published version is available at: [http://dx.doi.org/10.1117/12.2185802]. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper is prohibited and is subject to penalties under law.