Design of the VLTI/Hi-5 light injection system

G. Garreau, A. Bigioli, G. Raskina, C. Dandumont, J-P. Berger, Denis Defrère, Romain Laugier, M. Ireland, J.J.D. Loicq, More Authors

Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review

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Hi-5 is an ERC-funded project hosted at KU Leuven and a proposed visitor instrument for the VLTI. Its primary goal is to image the snow line region around young planetary systems using nulling interferometry in the L’ band, between 3.5 and 4.1 μm, where the contrast between exoplanets and their host stars is very advantageous. The breakthrough is the use of a photonic chip based beam combiner, which only recently allowed the required theoretical raw contrast of 10−3 in this spectral range. The VLTI long baseline interferometry enables to reach high angular resolution (4.2 mas at 3.8 μm wavelength with the Auxiliary Telescopes (ATs)), while high contrast detection is achieved using nulling interferometry. This polarisation requires a high degree of optical symmetry between the four pupils of the VLTI, only possible with precise phase, dispersion and intensity control systems. The instrument is currently in its design phase. In this paper, the warm optics design and the injection system up to the photonic chip are presented. The different properties of the design are presented including the optics used, the characteristics of the four beams and the current drawbacks. Particular attention is devoted to the optical alignment and the tolerance analysis in order to estimate the precision required for the alignment procedure and therefore to choose adapted optical mountings.
Original languageEnglish
Title of host publicationOptical and Infrared Interferometry and Imaging VIII
EditorsAntoine Mérand, Stephanie Sallum, Joel Sanchez-Bermudezv
Number of pages16
Publication statusPublished - 2022
EventSPIE Astronomical Telescopes + Instrumentation 2022 - Montréal, Canada
Duration: 17 Jul 202222 Jul 2022

Publication series

NameProceedings of SPIE
ISSN (Electronic)0277-786X


ConferenceSPIE Astronomical Telescopes + Instrumentation 2022

Bibliographical note

Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project
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