First fringes on the sky with an upconversion interferometer tested on a telescope Array

Pascaline Darré (1) , Laurent Delage (1) , Ludovic Grossard (1) , François Reynaud (1) , Romain Baudoin (1) , Jean-Thomas Gomes (2) , Nicholas J Scott (3) , Judit Sturmann (3) , Chris Farrington (3) , Theo ten Brummelaar (3)

1 XLIM-PHOT - Photonique Fibre et Sources Cohérentes
2 Novae
3 CHARA - Center for High Angular Resolution Astronomy

The Astronomical Light Optical Hybrid Analysis (ALOHA) project investigates the combined use of a telescope array interferometer and nonlinear optics to propose a new generation of instruments dedicated to high resolution imaging for infrared astronomy. The nonlinear process of optical frequency conversion transfers the astronomical light to a shorter wavelength domain. Here, we report on the first fringes obtained on the sky with the prototype operated at 1.55 µm in the astronomical H band and implemented on the Center for High Angular Resolution Astronomy (CHARA) telescope array. This seminal result allows us to foresee a future extension to the challenging mid-infrared spectral domain. PACS numbers: 42.65.Ky, 42.50.Ex, 07.60.Ly, 42.65.Wi, 95.55.Cs Many astronomical studies in the optical domain, such as Active Galactic Nuclei, Young Stellar Objects, formation and evolution of planetary systems require very accurate information in the order of milli-arcseconds. To achieve this level of performance, astronomical instruments have evolved from monolithic structures, with a maximum aperture diameter smaller than 10 m, to telescope arrays with a set of apertures separated by several hundred meters. In this operating framework, the observation of an astrophysical target does not produce classical images, but involves the analysis of the similarity between the optical waves collected by each elementary telescope through intensity [1, 2] or field correlation [3].

Domaines: Optique / photonique

Pascaline Darré, Laurent Delage, Ludovic Grossard, François Reynaud, Romain Baudoin, et al.. First fringes on the sky with an upconversion interferometer tested on a telescope Array. Physical Review Letters, 2016, 117 (23), ⟨10.1103/PhysRevLett.117.233902⟩. ⟨hal-02108717⟩