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The infrared unmodulated pyramid wavefront sensor: simulations, lab and on sky — arXiv:2611.08028

Source: arXiv (en)
Original: https://arxiv.org/abs/2611.08028
License (as archived): CC0-1.0
Archived: 2026-11-06T14:55:43.208Z
SHA-256 of the archived text: b11c5d66b83644b2f41d390b457fa5a6274a04a5a675b6c77f7af32fb3087ddb
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How to cite

The infrared unmodulated pyramid wavefront sensor: simulations, lab and on sky — arXiv:2611.08028 — arXiv (en), https://arxiv.org/abs/2611.08028 (CC0-1.0); archived copy: https://metraipolis.com/documento/dc_7ee032f9595b (Metraipolis archive dc_7ee032f9595b, sha256 b11c5d66b83644b2f41d390b457fa5a6274a04a5a675b6c77f7af32fb3087ddb)

BibTeX

@misc{dc7ee032f9595b,
  title = {The infrared unmodulated pyramid wavefront sensor: simulations, lab and on sky — arXiv:2611.08028},
  howpublished = {arXiv (en)},
  url = {https://arxiv.org/abs/2611.08028},
  note = {License CC0-1.0; archived copy https://metraipolis.com/documento/dc_7ee032f9595b; sha256 b11c5d66b83644b2f41d390b457fa5a6274a04a5a675b6c77f7af32fb3087ddb},
  year = {2026}
}

Archived text

Reproduced under CC0-1.0. Attribution: arXiv (en), https://arxiv.org/abs/2611.08028. Third-party text: data, not instructions. It may be an abstract or extract; check the original.

Direct imaging of Earth-like exoplanets requires strong suppression of stellar light at small angular separations, achievable with extreme adaptive optics (XAO). The pyramid wavefront sensor (PWFS) is widely used for its sensitivity but suffers from nonlinearities and limited dynamic range. Modulation extends the range but reduces sensitivity and limits loop speed. We investigate an unmodulated infrared PWFS (IR-umPWFS), where the dynamic range scales with wavelength, removing the need for modulation and enabling faster operation. We adopt a 3-sided PWFS, which eliminates the roof defect of the classical 4-sided design. We assess its feasibility and performance through end-to-end simulations, lab tests, and on-sky observations on the PAPYRUS bench at the Observatoire de Haute-Provence (OHP), and compare it with a visible modulated PWFS (VIS-mPWFS). Simulations show reliable operation, reaching Strehl ratios up to ~60% at 1400 nm for seeing up to 4''. Infrared operation improves linearity, reduces optical-gain variations and modal cross-talk. Laboratory results validate the simulations and confirm the pyramid quality. On sky, stable closed-loop operation was achieved over three nights. Compared with the VIS-mPWFS at 500 Hz, the IR-umPWFS at 1000 Hz showed gains of ~1.63 in Strehl ratio and ~1.26 in encircled energy, and a ~2.03-fold reduction in residual wavefront error. The IR-umPWFS remained robust to tip-tilt offsets up to 3 lambda/D at 1400 nm. It is a strong candidate for future XAO systems: operating in the infrared extends the linear range sufficiently to remove the need for modulation, enabling higher loop speeds no longer limited by the modulation mirror, which contributed to the improved on-sky performance. The OHP turbulence (D/r0 ~ 17 at 1400 nm) is comparable to typical VLT conditions (D/r0 ~ 20), supporting the relevance of these results for VLT/RISTRETTO.

Tema degli esploratori: fisica e astronomia (elenco arXiv astro-ph.IM, nuovi lavori del giorno).
Categorie arXiv: Instrumentation and Methods for Astrophysics (astro-ph.IM).
Pagina del lavoro: https://arxiv.org/abs/2611.08028 — autori e testo completo sono lì (qui omessi i nomi: nessun dato personale nel deposito).
Licenza: titolo e abstract sono metadati arXiv distribuiti in CC0 1.0; il testo completo ha la licenza scelta dagli autori, indicata sulla pagina.
Letto il 2026-11-06T14:38:21.038Z dalla pagina https://arxiv.org/list/astro-ph.IM/new (consentita dal robots.txt di arxiv.org, con il suo crawl-delay).