{
  "abstract": "The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system, fed by its upstream 3000-actuator \"woofer\" (AO3k), serves both as a platform for high contrast imaging (HCI) technology maturation and as a science instrument for imaging, spectroscopy, and polarimetry of exoplanets and disks. SCExAO operates in the visible and near-IR and offers a wide choice of instrument configurations. Over the last year, AO3k/SCExAO underwent significant upgrades to bring improved capabilities and support new developments, all while easing science operations. The new configuration features a beam switcher so that light can be shared between several instrument modules. The system is evolving toward a tighter integration between multiple WFSs and AO stages of correction, with the first stage (AO3k) providing visible and nearIR WFSing, as well as laser tomography. AO3k+SCExAO has been fully operational since October 2025, demonstrating very high stability on-sky, even in bad seeing conditions up to 2\". Having two XAO in series allows us to deploy advanced wavefront control techniques optimized for high-contrast imaging (e.g. speckle nulling, EFC, Coronagraphic LOWFS, Fast and Furious) on the second-stage XAO loop, as AO3k by itself delivers high-contrast PSFs already. Areas of active ongoing research include use of photonic devices for spectrally dispersed interferometric sensing, PSF reconstruction from WFS telemetry, and non-linear sensors (focal plane and curvature). Recent upgrades to the computer infrastructure are aimed at supporting these R\\&D efforts and providing a rich collaborative environment for experimentation. In this paper, we will present on-sky high-contrast performance characterization of AO3k, AO3k+SCExAO, and on-sky demonstrations of novel wavefront control techniques to improve the contrast behind the coronagraph.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2608.29572",
  "author_total": 8,
  "authors": [
    {
      "name": "Julien Lozi"
    },
    {
      "name": "Kyohoon Ahn"
    },
    {
      "name": "Vincent Deo"
    },
    {
      "name": "Olivier Guyon"
    },
    {
      "name": "Sandrine Juillard"
    },
    {
      "name": "Yoshito Ono"
    },
    {
      "name": "Garima Singh"
    },
    {
      "name": "Sébastien Vievard"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/ervzfmyq89s9w.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2608.29572",
  "fulltext_url": null,
  "id": "ervzfmyq89s9w",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2608.29572",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.IM"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2608.29572",
  "pmcid": null,
  "pmid": null,
  "published": "2026-08-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/ervzfmyq89s9w.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:20:12Z",
      "native_id": "2608.29572",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2608.29572"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.IM",
      "subfield": "instrumentation-methods"
    }
  ],
  "title": "AO3k + SCExAO: on-sky wavefront quality and demonstration of novel WFS techniques with the double XAO system",
  "title_text": "AO3k + SCExAO: on-sky wavefront quality and demonstration of novel WFS techniques with the double XAO system",
  "type": "preprint",
  "updated_at": "2026-10-30T12:20:12Z",
  "url": "https://research.draconitic.com/paper/ervzfmyq89s9w",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1117/12.3105833",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}