title: Phase closure retrieval in an infrared-to-visible upconversion interferometer for high resolution astronomical imaging.
abstract: This paper demonstrates the use of a nonlinear upconversion process to observe an infrared source through a telescope array detecting the interferometric signal in the visible domain. We experimentally demonstrate the possibility to retrieve information on the phase of the object spectrum of an infrared source by using a three-arm upconversion interferometer. We focus our study on the acquisition of phase information of the complex visibility by means of the phase closure technique. In our experimental demonstration, a laboratory binary star with an adjustable photometric ratio is used as a test source. A real time comparison between a standard three-arm interferometer and our new concept using upconversion by sum-frequency generation demonstrates the preservation of phase information which is essential for image reconstruction.
authors.affiliation: XLIM Département Photonique, Université de Limoges, UMR CNRS 6172, Limoges, France.
authors.forename: Damien
authors.initials: D
authors.lastname: Ceus
authors.forename: Alessandro
authors.initials: A
authors.lastname: Tonello
authors.forename: Ludovic
authors.initials: L
authors.lastname: Grossard
authors.forename: Laurent
authors.initials: L
authors.lastname: Delage
authors.forename: François
authors.initials: F
authors.lastname: Reynaud
authors.forename: Harald
authors.initials: H
authors.lastname: Herrmann
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Sohler
mesh_terms: D001256:Astronomy / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007259:Infrared Rays; D007368:Interferometry / Q000295:instrumentation*; D010783:Photometry / Q000295:instrumentation*; D012031:Refractometry / Q000295:instrumentation*