𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Profilometry with compact single-shot low-coherence time-domain interferometry

✍ Scribed by Molly Subhash Hrebesh; Yuuki Watanabe; Manabu Sato


Book ID
103873808
Publisher
Elsevier Science
Year
2008
Tongue
English
Weight
872 KB
Volume
281
Category
Article
ISSN
0030-4018

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✦ Synopsis


We describe the performance of a compact single-shot low-coherence interferometric scheme that can be capable of measuring three-dimensional surface profiles and shape. This technique utilizes a polarizing Michelson interferometer and a four-channel polarization phase-stepper optics, which is based on a paired wedge prism, a combined wave plate and a Wollaston prism. The coherence gated surface image can be calculated by the simultaneous acquisition of two interferograms and a DC image on a single CCD camera. The image calculation is based on a novel algorithm to calibrate the imbalanced intensity as well as the deviated arbitrary relative phase of each of the imaging channels. The system can display the transverse cross-sectional images in real-time. To demonstrate the feasibility of this system, a Japanese coin is presented as a 3-D shape measurement example with an image size of 4 mm (horizontal) Â 4 mm (vertical) Â 160 lm (depth).