The planar optics phase sensor: a study for the VLTI 2nd generation fringe tracker

Nicolas Blind, J.-B. Le Bouquin, Olivier Absil, Mazen Alamir, Jean-Philippe Berger, Denis Defrère, Philippe Feautrier, François Hénault, L. Jocou, Pierre Kern

Abstract

In a few years, the second generation instruments of the Very Large Telescope Interferometer (VLTI) will routinely provide observations with 4 to 6 telescopes simultaneously. To reach their ultimate performance, they will need a fringe sensor capable to measure in real time the randomly varying optical paths differences. A collaboration between LAOG (PI institute), IAGL, OCA and GIPSA-Lab has proposed the Planar Optics Phase Sensor concept to ESO for the 2^nd Generation Fringe Tracker. This concept is based on the integrated optics technologies, enabling the conception of extremely compact interferometric instruments naturally providing single-mode spatial filtering. It allows operations with 4 and 6 telescopes by measuring the fringes position thanks to a spectrally dispersed ABCD method. We present here the main analysis which led to the current concept as well as the expected on-sky performance and the proposed design.

Locations

• Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE - View
• arXiv (Cornell University) - View - PDF
• Open Repository and Bibliography (University of Liège) - View - PDF
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