US-France Cooperative Research: An Integrated Optics Beam Combiner for the CHARA Array

Georgia State University Research Foundation, Inc., Atlanta GA

Investigators

Abstract

0233138 McAlister This three-year award supports U.S.-France collaboration in optical long baseline interferometry for astronomy at Georgia State University and the Observatory of Grenoble. Harold A. McAlister leads the US group, which includes Stephen T. Ridgway of the National Optical Astronomy Observatories, Theo A. Ten Brummelaar of Georgia State and several graduate students. Jean-Philippe Berger, an astronomer at the Grenoble Observatory's Astrophysics Laboratory, leads the French group. The purpose of this US-France joint project is to develop and validate a new generation instrument capable of combining light from six telescopes at the Center for High Resolution Astronomy (CHARA) located in Mount Wilson, California. The new instrument will be based on technology developed by the Grenoble Observatory. This technology can replace dozens of precision fabricated and aligned optical components with a single optical "chip." The US group will develop the subsystems necessary to operate six telescopes simultaneously (including pair-wise fringe stabilization), will lead the design of the beam-combiner laboratory, and will develop optical and electronic interfaces. This is complemented by the Grenoble group's work on a combination system using integrated optics technologies. The goal is to obtain the first on-sky demonstration of an integrated optics beam combination at the CHARA array within the first year, and to obtain the first images with the full array at the conclusion of the grant period. This award represents the US side of joint proposals to the NSF and the French National Center for Scientific Research (CNRS). NSF will cover travel funds and living expenses for the US investigators and students. The CNRS will support the visits of the French researchers.