Adjustable dispersion reduction in low-coherent techniques by a system of tilted metallic mirrors with dielectric coating
Abstract
In this paper a new method for adjustable reduction of a dispersive drop in axial resolution during low-coherent measurements is presented. This method is based on multiple reflections of a light beam from dielectric coated metallic mirrors and is intended for reducing dispersion in full-field systems. The tilted metallic mirror with a dielectric coating works like an adjustable Gires-Tournois interferometer. The concept of adjustability is based on a polarization dependent phase shift upon reflection from metallic surfaces at incidence angles different from θi = 0 °. The dispersion compensation was simulated numerically with the use of Fresnel equations for a silver mirror based compensator. The possibility of dispersion reduction was then verified experimentally in a Twyman-Green interferometer showing over 40% improvement in the axial resolution.
- Publication:
-
Optics and Lasers in Engineering
- Pub Date:
- May 2015
- DOI:
- 10.1016/j.optlaseng.2014.12.017
- Bibcode:
- 2015OptLE..68..121T
- Keywords:
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- Low-coherence interferometry;
- Optical coherence tomography;
- Dispersion compensation