GPI 2.0: design of the pyramid wave front sensor upgrade for GPI

Fitzsimmons, Joeleff; Agapito, Guido; Bonaglia, Marco; Boucher, Marc-André; Chilcote, Jeffrey; Dunn, Jennifer; Esposito, Simone; Filion, Guillaume; Kerley, Daniel A.; Konopacky, Quinn; Landry, Jean-Thomas; Lardière, Olivier; Macintosh, Bruce; Madurowicz, Alexander; Maire, Jérôme; Marois, Christian; Poyneer, Lisa; Savransky, Dmitry; Véran, Jean-Pierre

doi:10.1117/12.2563150

Cited by 6 publications

(4 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…34 The PWFS is set up so that it mimics the GPI 2.0 PWFS, which uses an EMCCD220 with 60 pixels in the diameter of each of the four pupil images. 35 The PWFS is modeled to be sensitive to a 300-nm wide band centered on λ ¼ 750 nm. The flux available to the PWFS is derived from the magnitude value of the target, assuming an A0 star and affects the photon noise applied to the PWFS images.…”

Section: Data Sourcementioning

confidence: 99%

See 1 more Smart Citation

Mitigating the nonlinearities in a pyramid wavefront sensor

Archinuk,

Hafeez,

Fabbro

et al. 2023

J. Astron. Telesc. Instrum. Syst.

View full text Add to dashboard Cite

For natural guide star adaptive optics (AO) systems, pyramid wavefront sensors (PWFSs) can provide a significant increase in sensitivity over the traditional Shack-Hartmann but at the cost of a reduced linear range. When using a linear reconstructor, nonlinearities result in wavefront estimation errors, which can have a significant impact on the image quality delivered by the AO system. We simulate a wavefront passing through a PWFS under varying observing conditions to explore the possibility of using a nonlinear machine learning model to estimate wavefront errors and compare with a linear reconstruction. We find significant potential improvements in delivered image quality even with computationally simple models, underscoring the need for further investigation of this approach.

show abstract

Section: Data Sourcementioning

confidence: 99%

“…The PWFS is simulated using the physical optics PWFS module included in PASSATA 34 . The PWFS is set up so that it mimics the GPI 2.0 PWFS, which uses an EMCCD220 with 60 pixels in the diameter of each of the four pupil images 35 . The PWFS is modeled to be sensitive to a 300-nm wide band centered on λ=750 nm.…”

Section: Data Sourcementioning

confidence: 99%

Mitigating the nonlinearities in a pyramid wavefront sensor

Archinuk,

Hafeez,

Fabbro

et al. 2023

J. Astron. Telesc. Instrum. Syst.

View full text Add to dashboard Cite

show abstract

“…GPI 2.0 will be removing the existing spatially-filtered, Shack-Hartmann wavefront sensor and replacing it with a pyramid WFS leveraging the existing design studies performed for NFIRAOS. 38 NRC Herzberg Astronomy and Astrophysics is leading the design of the Pyramid WFS and construction, alignment and testing is being lead by the University of California, San Diego. This upgrade is being designed as an independent sub-bench to the existing AO bench and will replace the optical leg after the original system's beam splitter.…”

Section: Ao Upgrade: Improving Contrast and Limiting Magnitudementioning

confidence: 99%

GPI 2.0: upgrading the Gemini Planet Imager

Chilcote

Konopacky

Rosa³

et al. 2020

Ground-Based and Airborne Instrumentation for Astronomy VIII

Self Cite

View full text Add to dashboard Cite

The Gemini Planet Imager (GPI) is a dedicated high-contrast imaging facility designed for the direct detection and characterization of young Jupiter mass exoplanets. After six years of operation at Gemini South, GPI has helped establish that Jovian planets are rare at wide separations, but have higher occurrence rates at small separations. This motivates an upgrade of GPI to achieve deeper contrasts, especially at small inner working angles, while leveraging its current capabilities. GPI has been funded to undergo a major science-driven upgrade as part of a relocation to Gemini North (GN). Gemini plans to remove GPI at the end of 2020A. We present the status of the proposed upgrades to GPI including a EMCCD-based pyramid wavefront sensor, broadband low spectral resolution prisms and new apodized-pupil Lyot coronagraph designs. We discuss the expected

show abstract

“…Most current and future HCI instruments will use or are already using a Pyramid wavefront sensor (PWFS; Ragazzoni 1996) as their main WFS (e.g., Pinna et al 2016;Kasper et al 2021;Males et al 2022a,b;Haffert et al 2022;Bond et al 2022). Furthermore, upgrades of other HCI instruments are also planning to use a PWFS as a primary or second-stage WFS (Fitzsimmons et al 2020;Perera et al 2022;Boccaletti et al 2022). The increased preference for the PWFS over the Shack-Hartmann WFS is mostly due to its improved sensitivity (Ragazzoni & Farinato 1999;Chambouleyron et al 2023).…”

Section: Introductionmentioning

confidence: 99%

Making the unmodulated Pyramid wavefront sensor smart

Landman,

Haffert,

Males

et al. 2024

A&A

View full text Add to dashboard Cite

Almost all current and future high-contrast imaging instruments will use a Pyramid wavefront sensor (PWFS) as a primary or secondary wavefront sensor. The main issue with the PWFS is its nonlinear response to large phase aberrations, especially under strong atmospheric turbulence. Most instruments try to increase its linearity range by using dynamic modulation, but this leads to decreased sensitivity, most prominently for low-order modes, and makes it blind to petal-piston modes. In the push toward high-contrast imaging of fainter stars and deeper contrasts, there is a strong interest in using the PWFS in its unmodulated form. Here, we present closed-loop lab results of a nonlinear reconstructor for the unmodulated PWFS of the Magellan Adaptive Optics eXtreme (MagAO-X) system based on convolutional neural networks (CNNs). We show that our nonlinear reconstructor has a dynamic range of >600 nm root-mean-square (RMS), significantly outperforming the linear reconstructor that only has a 50 nm RMS dynamic range. The reconstructor behaves well in closed loop and can obtain >80<!PCT!> Strehl at 875 nm under a large variety of conditions and reaches higher Strehl ratios than the linear reconstructor under all simulated conditions. The CNN reconstructor also achieves the theoretical sensitivity limit of a PWFS, showing that it does not lose its sensitivity in exchange for dynamic range. The current CNN’s computational time is 690 mu s, which enables loop speeds of >1 kHz. On-sky tests are foreseen soon and will be important for pushing future high-contrast imaging instruments toward their limits.

show abstract

GPI 2.0: design of the pyramid wave front sensor upgrade for GPI

Cited by 6 publications

References 0 publications

Mitigating the nonlinearities in a pyramid wavefront sensor

Mitigating the nonlinearities in a pyramid wavefront sensor

GPI 2.0: upgrading the Gemini Planet Imager

Making the unmodulated Pyramid wavefront sensor smart

Contact Info

Product

Resources

About