GRAVITY faint: reducing noise sources in GRAVITY+ with a fast metrology attenuation system

Felix Widmann; Stefan Gillessen; Thomas Ott; Taro Shimizu; Frank Eisenhauer; Maximilian Fabricius; Julien Woillez; Frédéric Gonté; Matthew Horrobin; Jingyi Shangguan; Senol Yazici; Guy Perrin; Thibaut Paumard; Wolfgang Brandner; Laura Kreidberg; Christian Straubmeier; Karin Perraut; Jean-Baptiste Le Bouquin; Paulo Garcia; Sebastian Hönig; Denis Defrère; Guillaume Bourdarot; Antonia Drescher; Helmut Feuchtgruber; Reinhard Genzel; Michael Hartl; Dieter Lutz; Nikhil More; Christian Rau; Sinem Uysal; Ekkehard Wieprecht

doi:10.1117/12.2628813

26 August 2022 GRAVITY faint: reducing noise sources in GRAVITY+ with a fast metrology attenuation system

Felix Widmann, Stefan Gillessen, Thomas Ott, Taro Shimizu, Frank Eisenhauer, Maximilian Fabricius, Julien Woillez, Frédéric Gonté, Matthew Horrobin, Jingyi Shangguan, Senol Yazici, Guy Perrin, Thibaut Paumard, Wolfgang Brandner, Laura Kreidberg, Christian Straubmeier, Karin Perraut, Jean-Baptiste Le Bouquin, Paulo Garcia, Sebastian Hönig, Denis Defrère, Guillaume Bourdarot, Antonia Drescher, Helmut Feuchtgruber, Reinhard Genzel, Michael Hartl, Dieter Lutz, Nikhil More, Christian Rau, Sinem Uysal, Ekkehard Wieprecht

Author Affiliations +

Proceedings Volume 12183, Optical and Infrared Interferometry and Imaging VIII; 121830U (2022) https://doi.org/10.1117/12.2628813
Event: SPIE Astronomical Telescopes + Instrumentation, 2022, Montréal, Québec, Canada

Abstract

With the upgrade from GRAVITY to GRAVITY+ the instrument will evolve to an all-sky interferometer that can observe faint targets, such as high redshift AGN. Observing the faintest targets requires reducing the noise sources in GRAVITY as much as possible. The dominant noise source, especially in the blue part of the spectrum, is the backscattering of the metrology laser light onto the detector. To reduce this noise we introduce two new metrology modes. With a combination of small hardware changes and software adaptations, we can dim the metrology laser during the observation without losing the phase referencing. For single beam targets, we can even turn off the metrology laser for the maximum SNR on the detector. These changes lead to a SNR improvement of over a factor of two averaged over the whole spectrum and up to a factor of eight in the part of the spectrum currently dominated by laser noise.

Conference Presentation

Citation Download Citation

Felix Widmann, Stefan Gillessen, Thomas Ott, Taro Shimizu, Frank Eisenhauer, Maximilian Fabricius, Julien Woillez, Frédéric Gonté, Matthew Horrobin, Jingyi Shangguan, Senol Yazici, Guy Perrin, Thibaut Paumard, Wolfgang Brandner, Laura Kreidberg, Christian Straubmeier, Karin Perraut, Jean-Baptiste Le Bouquin, Paulo Garcia, Sebastian Hönig, Denis Defrère, Guillaume Bourdarot, Antonia Drescher, Helmut Feuchtgruber, Reinhard Genzel, Michael Hartl, Dieter Lutz, Nikhil More, Christian Rau, Sinem Uysal, and Ekkehard Wieprecht "GRAVITY faint: reducing noise sources in GRAVITY+ with a fast metrology attenuation system", Proc. SPIE 12183, Optical and Infrared Interferometry and Imaging VIII, 121830U (26 August 2022); https://doi.org/10.1117/12.2628813

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available