Single-shot low coherence pointwise measuring interferometer with potential for in-line inspection
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2016-12-29 |
| Journal | Measurement Science and Technology |
| Authors | Robin Hahn, Johann Krauter, Klaus Kƶrner, Marc Gronle, Wolfgang Osten |
| Institutions | University of Stuttgart |
| Citations | 11 |
Abstract
Section titled āAbstractāLow-coherence-interferometry (LCI) is a well-known optical metrology technique which offers high resolution and a low measurement uncertainty. For the inspection of dynamic and fast processes, single-shot point sensors can show their full capability. Therefore, a new approach of an interferometer is presented, allowing an single-shot acquisition of a LCI signal. The presented concept is based on tilted wavefronts to generate a spatial modulated interferogram. Using a three faceted mirror (TFM) in the reference path, a virtual field point is generated leading to a tilted planar reference wavefront in the pupil plane of the telecentric objective lens. Three mirror surfaces, which are diamond milled out of a monolithic copper cube, are applied to guarantee a stable TFM geometry, resulting in an invariant reference field point position.