New NIR spectro-polarimetric modes for the SCExAO instrument

Julien Lozi, Olivier Guyon, Tomoyuki Kudo, Jin Zhang, Nemanja Jovanovic, Barnaby Norris, Marc Antoine Martinod, Tyler D. Groff, Jeffrey Chilcote, Motohide Tamura, Steven Bos, Frans Snik, Sébastien Vievard, Ananya Sahoo, Vincent Deo, Frantz Martinache, Jeremy Kasdin

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

4 Scopus citations


Polarization Differential Imaging (PDI) is one of the most productive modes of current high-contrast imagers. Dozens of new protoplanetary, transition and debris disks were imaged recently for the first time, helping us understand the processes of planet formation, and giving clues on the mass of potential planets inside these disks, even if they cannot be imaged directly. The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument is equipped with a fast visible dual-camera polarimetric module, VAMPIRES, already producing valuable scientific observations of protoplanetary disks and dust shells. In addition, we recently commissioned two new polarimetric modules in the infrared. The first one is a spectro-polarimetric mode using the CHARIS Integral Field Spectrograph (IFS). A Wollaston prism was added in front of the IFS, reducing the field-of-view to 2x1 arcsec to accommodate for the imaging of both polarizations on the same detector without sacrificing the spectral resolution of the instrument, in any of its spectral modes. The second module, similar to VAMPIRES, uses a low-noise high frame rate C-RED ONE camera combined with a Ferroelectric Liquid Crystal (FLC) device to modulate and record the polarization at high-speed, freezing effectively the atmospheric speckles for higher precision. We present on-sky results of the new polarimetric capabilities taken during the commissioning phase. In addition, we show future capabilities that are already scheduled to increase the performance of these modules, especially the addition of non-redundant masks, as well as a polarimetric vector Apodizing Phase Plate (vAPP) coronagraph.

Original languageEnglish (US)
Title of host publicationAdaptive Optics Systems VII
EditorsLaura Schreiber, Dirk Schmidt, Elise Vernet
ISBN (Electronic)9781510636835
StatePublished - 2020
EventAdaptive Optics Systems VII 2020 - Virtual, Online, United States
Duration: Dec 14 2020Dec 22 2020

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X


ConferenceAdaptive Optics Systems VII 2020
Country/TerritoryUnited States
CityVirtual, Online


  • Adaptive optics
  • High-contrast imaging
  • Polarimetry
  • Spectro-polarimetry

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


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