Upgrading the Gemini Planet Imager calibration unit with a photon counting focal plane wavefront sensor

Christian Marois, B. Gerard, O. Lardière, A. Anthony, C. Bradley, J. Dunn, Qiang Fu, T. Hardy, Wolfgang Heidrich, G. Herriot, E. Nielsen, S. Sivanandam, D. Sivransky, S. Thibault, W. Thompson, J. P. Véran

Research output: Chapter in Book/Report/Conference proceedingConference contribution

13 Scopus citations


High-contrast imaging instruments have advanced techniques to improve contrast, but they remain limited by uncorrected stellar speckles, often lacking a "second stage"correction to complement the Adaptive Optics (AO) correction. We are implementing a new second stage speckle-correction solution for the Gemini Planet Imager (GPI), replacing the instrument calibration unit (CAL) with the Fast Atmospheric Self coherent camera Technique (FAST), a new version of the self-coherent camera (SCC) concept. Our proposed upgrade (CAL2.0) will use a common-path interferometer design to enable speckle correction, through post-processing and/or by a feedback loop to the AO deformable mirror. FAST utilizes a new type of coronagraphic mask that will enable, for the first time, speckle correction down to millisecond timescales. The system's main goal is to improve the contrast by up to 100x in a halfdark hole to enable a new regime of science discoveries. Our team has been developing this new technology at the NRC's Extreme Wavefront control for Exoplanet and Adaptive optics Research Topics (NEW EARTH) laboratory over the past several years. The GPI CAL2.0 update is funded (November 2020), and the system's first light is expected late 2023.
Original languageEnglish (US)
Title of host publicationAdaptive Optics Systems VII
ISBN (Print)9781510636835
StatePublished - Dec 14 2020

Bibliographical note

KAUST Repository Item: Exported on 2021-02-23
Acknowledgements: The authors thank the NRC Ideation Fund and CAL2.0 collaborators. We acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC). The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community.We are most fortunate to have the opportunity to conduct observations from this mountain.


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