Active Correction of Aperture Discontinuities-Optimized Stroke Minimization. II. Optimization for Future Missions

Mazoyer, J.; Pueyo, Laurent; N’Diaye, Mamadou; Fogarty, Kevin; Zimmerman, Neil; Soummer, Rémi; Shaklan, Stuart; Norman, Colin

doi:10.3847/1538-3881/aa91d7

Cited by 35 publications

(40 citation statements)

References 58 publications

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“…We fit a line to the increasing slope of this curve and found contrast degrades as F 2 as expected from the C DH,2 contrast residual. We do not explain the limitation at small Fresnel number in this proceedings but in an upcoming article 19 For throughput, we see that the throughput performance is almost flat until F ∼ 10 3 but then decreases quickly at higher Fresnel numbers. However, one has to remember that we assumed that the surface outside of the second DM is reflective, although not actuated.…”

Section: End-to-end Simulation With the Acad-osm Methods And The Wfirsmentioning

confidence: 89%

“…The active correction for aperture discontinuities technique (ACAD) [14][15][16] was developed for this reason, and improved recently into the active correction for aperture discontinuities technique-opimized stroke minimization (ACAD-OSM, see paper #10400-16, Mazoyer et al, in these proceedings) technique. [17][18][19] However, the use of DMs for active correction comes with limitations that have to be understand to help the design of the instruments.…”

Section: Introductionmentioning

confidence: 99%

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Fundamental limits to high-contrast wavefront control

Mazoyer

Pueyo

2017

Techniques and Instrumentation for Detection of Exoplanets VIII

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The current generation of ground-based coronagraphic instruments uses deformable mirrors to correct for phase errors and to improve contrast levels at small angular separations. Improving these techniques, several space and ground based instruments are currently developed using two deformable mirrors to correct for both phase and amplitude errors. However, as wavefront control techniques improve, more complex telescope pupil geometries (support structures, segmentation) will soon be a limiting factor for these next generation coronagraphic instruments.In this paper we discuss fundamental limits associated with wavefront control with deformable mirrors in high contrast coronagraph. We start with an analytic prescription of wavefront errors, along with their wavelength dependence, and propagate them through coronagraph models. We then consider a few wavefront control architectures, number of deformable mirrors and their placement in the optical train of the instrument, and algorithms that can be used to cancel the starlight scattered by these wavefront errors over a finite bandpass. For each configuration we derive the residual contrast as a function of bandwidth and of the properties of the incoming wavefront.This result has consequences when setting the wavefront requirements, along with the wavefront control architecture of future high contrast instrument both from the ground and from space. In particular we show that these limits can severely affect the effective Outer Working Angle that can be achieved by a given coronagraph instrument.

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Section: End-to-end Simulation With the Acad-osm Methods And The Wfirsmentioning

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Fundamental limits to high-contrast wavefront control

Mazoyer

Pueyo

2017

Techniques and Instrumentation for Detection of Exoplanets VIII

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“…A first implementation of adaptive coronagraphy is through leveraging of the DM(s) to dig coronagraphic dark holes. 2 The most generic formulation for any telescope aperture is through the Active Correction of Aperture Discontinuities, 29 which uses the common two-DM architecture of space-based high-contrast systems to augment the coronagraphic performance. Novel optical elements that derive from the display/projector industry are currently being successfully tested for adaptive coronagraphy with a large number of degrees of freedom (i.e.…”

Section: Adaptive Coronagraphymentioning

confidence: 99%

Review of high-contrast imaging systems for current and future ground-based and space-based telescopes III: technology opportunities and pathways

Snik

Absil

Baudoz

et al. 2018

Advances in Optical and Mechanical Technologies for Telescopes and Instrumentation III

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The Optimal Optical Coronagraph Workshop at the Lorentz Center in September 2017 in Leiden, the Netherlands gathered a diverse group of 25 researchers working on exoplanet instrumentation to stimulate the emergence and sharing of new ideas. This contribution is the final part of a series of three papers summarizing the outcomes of the workshop, and presents an overview of novel optical technologies and systems that are implemented or considered for high-contrast imaging instruments on both ground-based and space telescopes. The overall objective of high contrast instruments is to provide direct observations and characterizations of exoplanets at contrast levels as extreme as 10 −10 . We list shortcomings of current technologies, and identify opportunities and development paths for new technologies that enable quantum leaps in performance. Specifically, we discuss the design and manufacturing of key components like advanced deformable mirrors and coronagraphic optics, and their amalgamation in "adaptive coronagraph" systems. Moreover, we discuss highly integrated system designs that combine contrast-enhancing techniques and characterization techniques (like high-resolution spectroscopy) while minimizing the overall complexity. Finally, we explore extreme implementations using all-photonics solutions for ground-based telescopes and dedicated huge apertures for space telescopes.

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“…The Electric Field Conjugation technique (EFC) derives a DM setting required to achieve a desired electric field in the focal plane ). The performance of these techniques can be improved using regularization terms to account for example for the obstructed apertures or the use of two DMs (Pueyo et al 2009;Mazoyer et al 2018) or in the case of large aberrations (Herscovici-Schiller et al 2018a). All these techniques (WFS and WFC) have been developed and tested independently in laboratories in different environmental conditions (Mazoyer et al 2019).…”

Section: Introductionmentioning

confidence: 99%

Comparing focal plane wavefront control techniques: Numerical simulations and laboratory experiments

Potier

Baudoz

Galicher

et al. 2020

A&A

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Context. Fewer than 1% of all exoplanets detected to date have been characterized on the basis of spectroscopic observations of their atmosphere. Unlike indirect methods, high-contrast imaging offers access to atmospheric signatures by separating the light of a faint off-axis source from that of its parent star. Forthcoming space facilities, such as WFIRST/LUVOIR/HabEX, are expected to use coronagraphic instruments capable of imaging and spectroscopy in order to understand the physical properties of remote worlds. The primary technological challenge that drives the design of these instruments involves the precision control of wavefront phase and amplitude errors. To suppress the stellar intensity to acceptable levels, it is necessary to reduce phase aberrations to less than several picometers across the pupil of the telescope. Aims. Several focal plane wavefront sensing and control techniques have been proposed and demonstrated in laboratory to achieve the required accuracy. However, these techniques have never been tested and compared under the same laboratory conditions. This paper compares two of these techniques in a closed loop in visible light: the pair-wise (PW) associated with electric field conjugation (EFC) and self-coherent camera (SCC). Methods. We first ran numerical simulations to optimize PW wavefront sensing and to predict the performance of a coronagraphic instrument with PW associated to EFC wavefront control, assuming modeling errors for both PW and EFC. Then we implemented the techniques on a laboratory testbed. We introduced known aberrations into the system and compared the wavefront sensing using both PW and SCC. The speckle intensity in the coronagraphic image was then minimized using PW+EFC and SCC independently. Results. We demonstrate that both techniques -SCC, based on spatial modulation of the speckle intensity using an empirical model of the instrument, and PW, based on temporal modulation using a synthetic model -can estimate the wavefront errors with the same precision. We also demonstrate that both SCC and PW+EFC can generate a dark hole in space-like conditions in a few iterations. Both techniques reach the current limitation of our laboratory bench and provide coronagraphic contrast levels of ∼ 5.10 −9 in a narrow spectral band (<0.25% bandwidth). Conclusions.Our results indicate that both techniques are mature enough to be implemented in future space telescopes equipped with deformable mirrors for high-contrast imaging of exoplanets.

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Active Correction of Aperture Discontinuities-Optimized Stroke Minimization. II. Optimization for Future Missions

Cited by 35 publications

References 58 publications

Fundamental limits to high-contrast wavefront control

Fundamental limits to high-contrast wavefront control

Review of high-contrast imaging systems for current and future ground-based and space-based telescopes III: technology opportunities and pathways

Comparing focal plane wavefront control techniques: Numerical simulations and laboratory experiments

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