2004/02/13 by E. Tatulli, P. Mege, P. Mège +1 · 1 citation
Engineering · Physics and Astronomy · #Adaptive optics #Adaptive optics and wavefront sensing #Astronomical interferometer #Interferometry #Multi-mode optical fiber #Optical Wireless Communication Technologies #Speckle pattern #Stellar, planetary, and galactic studies #Strehl ratio #Visibility #Wavefront #astro-ph
paper · pdf · doi:10.1051/0004-6361:20034090
published as Astron.Astrophys. 418 (2004) 1179-1186 · 13 pages (5 pages of appendices), 6 figures to be published in A&A
arxiv created 2004/02/13 · openalex publication_date 2004/04/16 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We compare performances of ground-based single-mode and multimode (speckle) interferometers in the presence of partial Adaptive Optics correction of atmospheric turbulence. It is first shown that for compact sources (i.e. sources smaller than the Airy disk of a single telescope) not entirely resolved by the interferometer, the remarkable property of spatial filtering of single-mode waveguides coupled with AO correction significantly reduces the speckle noise which arises from residual wavefront corrugations. Focusing on those sources, and in the light of the AMBER experiment (the near infrared instrument of the VLTI), we show that single-mode interferometry produces a better Signal-to-Noise Ratio on the visibility than speckle interferometry. This is true for bright sources (), and in any case as soon as Strehl ratio of 0.2 is achieved. Finally, the fiber estimator is much more robust – by two orders of magnitude – than the speckle estimator with respect to Strehl ratio variations during the calibration procedure. The present analysis theoretically explains why interferometry with fibers can produce visibility measurements with a very high precision, or less.