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Cascade adaptive optics with a second stage based on a Zernike wavefront sensor for exoplanet observations

T0 review · 3 major / 5 minor · reviewed 2026-08-12 · deepseek-v4-flash

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Pith's one-line read This paper demonstrates that a Zernike wavefront sensor can drive the second stage of a cascade adaptive optics system, reducing atmospheric residuals by a factor of 6 and raising coronagraph contrast by up to a factor of 2 in a testbed.

desk verdict First systematic lab validation of a ZWFS second-stage AO loop; the factor-6 residual reduction is robust, but the contrast-gain headline is underpowered and the transfer to on-sky rests on an unvalidated synthetic-residual assumption. read the letter →

arxiv 2411.11946 v2 pith:RJUPUF3J submitted 2024-11-18 astro-ph.IM astro-ph.EP

M. N'Diaye , A. Vigan , B. Engler , M. Kasper , K. Dohlen , S. Leveratto , J. Floriot , M. Marcos
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C. Bailet P. Bristow
This is my paper · ORCID
classification astro-ph.IMastro-ph.EP
keywords adaptiveopticsZernikewavefrontsensorcascadeAOhigh-contrastimagingcoronagraphyexoplanetresidualssensing
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper tries to establish that a Zernike wavefront sensor (ZWFS) can serve effectively as the second stage of a cascade adaptive optics system, mopping up the small atmospheric residuals that an extreme adaptive optics (XAO) first stage leaves behind. On a laboratory testbed that replays realistic simulated XAO residuals, the authors close a ZWFS-based control loop with a simple integrator and measure a factor-of-6 reduction in wavefront error and a factor-of-2 gain in stability in median wind and seeing conditions. With a Lyot coronagraph and in the presence of non-common path aberrations, the loop delivers a contrast gain of up to a factor of 2 at short separations, reaching the experiment's own contrast floor out to 8 $\lambda/D$. These results support the idea that a ZWFS second stage, which needs no modulation and can run at high speed, is a viable alternative or complement to the pyramid wavefront sensor baseline for future exoplanet imagers.

What carries the argument

The central object is the Zernike wavefront sensor (ZWFS), a phase-contrast device consisting of a small phase-shifting dot (diameter $1.05\lambda/D$, phase shift $\pi/2$) at the focal plane that turns small phase aberrations into measurable intensity variations in a relayed pupil. In the linear regime (aberrations within $\pm 0.05\lambda$), the phase is reconstructed from the intensity using a relation of the form $\varphi = (I_C - I_0^C)/(2 P b \sin\theta)$, and the control loop builds a command matrix from an interaction matrix measured by sending Hadamard modes to the deformable mirror. The sensor's high sensitivity and lack of moving parts are what allow the second stage to run a simple integrator at 350 Hz (demonstrated up to 5 kHz) and correct the low-order residuals that dominate the XAO error budget.

What would settle it

Replay the same second-stage ZWFS loop with residual phase screens that come from a different source than the simulation used here—for example, residuals recorded on sky with a real XAO system or generated by an independent simulation code with a different deformable-mirror geometry and loop delay—and check whether the factor-of-6 wavefront error reduction and the factor-of-2 coronagraphic contrast gain still appear; if they do not, the result is tied to the specific simulated residual model rather than to the ZWFS stage's intrinsic capability.

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Extended reading notes

Core claim

On the GHOST testbed, a spatial light modulator replays residual phase screens derived from a numerical simulation of a VLT/SPHERE-like XAO system (800 KL modes at 1 kHz, saved at 2 kHz, replayed at 350 Hz). Closing a ZWFS-based loop that controls 350 KL modes with a leaky integrator (gain 0.8, leak 0.99) reduces the temporal RMS wavefront error from $(7.4 \pm 0.6)\times10^{-3}$ V to $(1.2 \pm 0.3)\times10^{-3}$ V, a factor of 6, in median conditions (10 m/s wind, 0.7" seeing), and cuts the temporal dispersion by a factor of 2. In the science arm with a classical Lyot coronagraph and 20 nm RMS of uncorrected non-common path aberrations, the closed loop improves contrast by up to a factor of 2 at separations of 2 to 11$\lambda/D$ in monochromatic light at 770 nm, reaching the experimental contrast floor out to 8$\lambda/D$. The paper presents this as the first in-lab validation of a ZWFS-based second-stage AO loop for high-contrast exoplanet observations.

Load-bearing premise

The whole demonstration rests on the assumption that the residual phase screens replayed by the spatial light modulator are representative of the spatial, temporal, and chromatic structure of the wavefront errors a real XAO instrument leaves behind; if real residuals differ in those statistics, the measured factors of 6 and 2 may not transfer to on-sky cascade operation.

Editorial extensions

If this is right

  • A ZWFS-based second stage could be added to existing XAO instruments without replacing the first stage, lowering wavefront residuals by a factor of 6 in median conditions and allowing fainter companions to be imaged at separations down to about 11$\lambda/D$.
  • Because the ZWFS requires no modulation and can be read out four times faster than a pyramid sensor over the same detector area, second-stage loops could run at several kilohertz, extending correction into high-wind regimes where a single XAO stage is servo-lag limited.
  • The low-flux comparison suggests the ZWFS loop with an adjusted integrator gain can hold its contrast performance down to about 2.9 magnitudes below the reference flux and, at $\Delta$mag = 5, achieve deeper contrasts than a modulated pyramid loop at its optimal gain.
  • The measured contrast gain of 2 is limited by the classical Lyot coronagraph and by 20 nm of uncorrected non-common path aberrations; with a deeper coronagraph and NCPA calibration, the much larger wavefront error reduction (factor 6) would translate into larger contrast gains.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If the factor-6 wavefront reduction scales to physical nanometers on sky, an XAO system leaving about 85 nm RMS residual would be brought to roughly 14 nm RMS by the second stage, a regime in which the Zernike sensor's linear reconstruction could continue to work only if the residual statistics remain within its $\pm 0.05\lambda$ capture range.
  • The testbed demonstration uses monochromatic light; a natural next step would be a polychromatic version, and if the gains survive broadband operation the scheme could be directly considered for 8-10 m class instruments and ELTs.
  • The low-flux advantage over the pyramid sensor comes from a single configuration and could shift with different modulation, readout noise, or residual amplitudes; the two sensors may prove complementary rather than competitive, with the ZWFS chosen for high-speed operation and the PWFS for larger capture range.
  • Integrating the second-stage loop with the first-stage telemetry (rather than running standalone) would likely improve the end-to-end correction, since the two loops currently treat the residuals as an external disturbance.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 5 minor

Summary. The paper proposes and experimentally validates on the ESO/GHOST testbed a second-stage adaptive-optics loop based on a Zernike wavefront sensor (ZWFS) to correct residuals left by an extreme adaptive optics (XAO) first stage. Residual phase screens from OOPAO simulations of a PWFS-based XAO (800 KL modes, 1 kHz) are replayed on a spatial light modulator, and a ZWFS-driven loop with a leaky integrator, controlling up to 350 KL modes at 350 Hz, is closed around a Boston Micromachines DM. In median conditions (10 m/s wind, 0.7" seeing), the authors report a factor-6 reduction in the temporal RMS of DM-command wavefront errors (7.4±0.6 vs 1.2±0.3 in 10^-3 V), a factor-2 improvement in temporal stability, and a factor-2 gain in Lyot-coronagraph contrast at short separations. Additional experiments explore wind speed, seeing, source flux, number of corrected modes, loop gain, field-stop size, and calibration, and include a low-flux comparison with a modulated PWFS loop.

Significance. If the result holds, the paper provides the first in-lab demonstration that a ZWFS can serve as a fast, sensitive second stage for a cascade AO system, offering a modulation-free alternative to the PWFS baseline for high-contrast exoplanet imagers such as SPHERE+ and future ELT instruments. The factor-6 residual reduction is well supported by the independent DM-command time series, whose error bars do not overlap, and the coronagraphic images provide a partially independent metric of improvement. The exploration of control parameters (Nmodes, gain, field stop, calibration) and the low-flux comparison with the PWFS are useful for future system design. The main fragility is external validity: every headline gain is measured on synthetic first-stage residuals, and the contrast-gain claim at 5 lambda/D has overlapping 1-sigma error bars in Table B.1.

major comments (3)
  1. [Section 2.3 and Sections 3.2-3.3] The claim that the OOPAO residual screens replayed by the SLM 'provide a realistic representation of the atmospheric wavefront errors left after correction by an XAO instrument such as VLT/SPHERE' is stated without quantitative support. The paper does not compare the spatial KL spectrum or temporal PSD of the replayed screens with on-sky XAO telemetry or with published residual statistics, and it does not characterize the SLM's fidelity in reproducing the OOPAO phase maps. Since the factor-6 residual reduction, the factor-2 stability gain, and the factor-2 contrast gain in Section 3 are all measured against these synthetic inputs, this representativeness assumption is load-bearing for the paper's conclusion that the ZWFS second stage is effective for real exoplanet imagers. I request either a quantitative validation (e.g., comparison with SPHERE/SAXO telemetry or a sensitivity study varying the injected residual statistics) or a clear re-scoping of the conclusions to the synthetic-residual testbed case.
  2. [Table B.1 and Fig. 6] The headline contrast gain of a factor of 2 at 5 lambda/D in median conditions is based on azimuthally averaged contrast values of (12.4±5.5) x 10^-5 open loop and (6.5±4.0) x 10^-5 closed loop, whose 1-sigma error bars overlap. The factor of 1.9 is therefore not statistically significant at the 1-sigma level with the quoted uncertainties. The factor-6 wavefront-error reduction in Fig. 3 has non-overlapping error bars and is the robust part of the demonstration. The authors should either add more independent frames or a proper statistical test to support the contrast-gain claim, or present it clearly as indicative rather than as a demonstrated factor-2 gain in the abstract and conclusions.
  3. [Section 3.2 and Fig. 3] The factor-6 'wavefront error' reduction is quantified in normalized DM command voltages (10^-3 V), not in physical units of optical path difference or nanometers. The linearity of the DM command-to-phase relationship and the reconstruction calibration are internal to the loop, so the voltage-space factor may not equal the phase-space reduction factor. The abstract and conclusions state the result as a reduction of 'atmospheric residuals' without this qualification. Since the coronagraphic contrast improvement provides independent evidence of real correction, this is not a fatal issue, but the authors should explicitly state that the factor-6 metric is in DM-command space, or provide the conversion to nanometers.
minor comments (5)
  1. [Section 4.1] The text states that 'contrast gain larger than 10' is achieved for wind speeds larger than 10 m/s, but Table B.1 lists gains of 5.9 and 9.8 at 5 lambda/D for 24 and 34 m/s, respectively; please specify the separation at which the gain exceeds 10 or adjust the statement to match the tabulated values.
  2. [Eq. (3)] The numerator in the displayed formula for phi is missing parentheses: it should be (I_C - P^2 + 2b(1-cos theta)(P-b)) / (2Pb sin theta).
  3. [Section 3.2] There is a typo in 'studies are on going' (should be 'ongoing').
  4. [Fig. 5 caption] The caption refers to the PSD 'displayed in Fig. 3 (bottom plot)'; use 'bottom panel' for consistency with other captions.
  5. [Section 2.1] The acronym GHOST is expanded as 'GPU-based High-order adaptive OpticS Testbench' but the phrase 'GPU-based' is not further defined; a brief note on the GPU real-time computer would help readers, though COSMIC is described later in Section 2.3.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the headline gains are independent testbed measurements, and the synthetic XAO-residual assumption is an external-validity caveat, not a fitted input or derivation premise.

full rationale

The paper's central performance claims—factor-of-6 wavefront-error reduction, factor-of-2 temporal-stability gain, and factor-of-2 coronagraphic contrast gain—are measured quantities on the GHOST testbed, not derived quantities that reduce to the calibration inputs. The ZWFS linear model (Eqs. 1–4) is taken from the authors' earlier published work (N'Diaye et al. 2013), but that is a peer-reviewed, independently checkable result and is not used to forbid alternatives or to force the loop performance; the command matrix is obtained from measured interaction matrices (Section 2.3), and the loop's success is verified independently in the science arm via the Lyot-coronagraph images (Section 3.3). The only self-referential-looking element is that the WFS-path residual is expressed in normalized DM commands produced by the same control matrix, but this is standard AO telemetry and it is corroborated by the independent coronagraphic contrast and temporal PSD measurements. Explicitly weighed limitations: Section 2.3's assertion that the OOPAO residual screens 'provide a realistic representation of the atmospheric wavefront errors left after correction by an XAO instrument such as VLT/SPHERE' is an external-validity assumption about input fidelity, not circularity; Section 5.1's 'it is obviously risky to draw hasty conclusions' and Section 6's 'on-sky demonstration is a crucial step' and 'performed in monochromatic light' concern technology readiness, not whether the measured performance is implied by the calibration. Table B.1's overlapping error bars on some contrast gains are a statistical-significance concern, not a circularity concern. No step of the claimed derivation reduces, by construction or by self-citation, to its own input.

Assumptions & free parameters 4 free parameters · 4 assumptions · 0 invented entities

The central claim rests on hand-tuned AO control parameters (gain, Nmodes, leak, field stop) and on several domain assumptions, most importantly that simulated XAO residuals replayed on the SLM represent real on-sky residuals. No new physical entities or free parameters in a derivation are introduced; the free parameters are experimental operating points.

free parameters (4)
  • Integrator gain = 0.8 nominal, 0.15 in low-flux ZWFS, 0.03 in low-flux PWFS
    Hand-tuned control parameter; Appendix A.2 shows it has no effect on contrast in median conditions, but it must be reduced to avoid noise amplification at low flux (Section 4.3, Fig. 10).
  • Number of corrected KL modes Nmodes = 350 nominal, reduced to 300 for 1.0 arcsec seeing and 250 for 34 m/s wind
    Chosen per observing condition; the loop breaks for large residuals and is stabilized by reducing Nmodes (Sections 4.1 and 4.2).
  • Loop leak = 0.99
    Chosen to mimic standard leaky integrator AO control (Section 2.3); no further justification is given.
  • Field stop diameter = 35 lambda/D nominal, 49 lambda/D tested
    Larger field stop degrades contrast gain from 2 to 1.5 (Appendix A.3); the smallest stop is selected for the headline results.
assumptions (4)
  • domain assumption ZWFS linear response is valid for aberrations within +/-0.05 lambda (Eqs. 3 and 4)
    Phase retrieval and the command matrix assume the small-aberration linear regime; the loop is known to diverge when residuals exceed the linear capture range (Section 4.1, 34 m/s case).
  • domain assumption OOPAO-generated residual phase screens are representative of VLT/SPHERE XAO residuals
    Section 2.3 states the simulated residuals 'provide a realistic representation' of XAO residuals, but this is asserted rather than verified against on-sky data.
  • domain assumption DM command residuals are proportional to wavefront phase errors
    The factor 6 reduction is reported in normalized DM command volts (Section 2.3), a proxy for wavefront error only if the DM influence functions and linear reconstructor justify the mapping.
  • domain assumption The two-step calibration with ZWFS flat reference yields a stable loop
    Setting reference slopes to a flat ZWFS response introduces a static aberration but improves stability (Appendix A.4); the loop behavior depends on this calibration choice.

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Cite this review

Pith. "Pith review of Cascade adaptive optics with a second stage based on a Zernike wavefront sensor for exoplanet observations." pith.science (2026). https://pith.science/paper/RJUPUF3J

@misc{pith2026241111946,
  author       = {Pith},
  title        = {Pith review of: Cascade adaptive optics with a second stage based on a Zernike wavefront sensor for exoplanet observations},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/RJUPUF3J}},
  note         = {Machine review of arXiv:2411.11946}
}
read the original abstract

Over the past decade, the high-contrast observation of disks and gas giant planets around nearby stars has been made possible on ground-based instruments using extreme adaptive optics (XAO). While these facilities produce images with a Strehl ratio larger than 90% in H-band in median observing conditions and high-flux regime, the correction leaves AO residuals which impede the study of fainter or less massive exoplanets. Cascade AO systems with a fast second stage based on a Pyramid wavefront sensor have recently emerged as an appealing solution to reduce the atmospheric wavefront errors. Since these aberrations are expected to be small, they can also be accurately measured by a Zernike wavefront sensor (ZWFS), a well-known concept for its high sensitivity and moderate linear capture range. We propose an alternative second stage that relies on the ZWFS to correct for the AO residuals. We implemented the cascade AO with a ZWFS-based control loop on the ESO's GHOST testbed to validate the scheme in monochromatic light. In median wind speed and seeing, our second-stage AO with a ZWFS and a basic integrator reduce the atmospheric residuals by a factor of 6 and increase the wavefront error stability with a gain of 2 from open to closed loop. In the presence of non common path aberrations, we also reach a contrast gain by a factor of 2 in the images with a Lyot coronagraph at short separations from the source, proving the ability of our scheme to work in cascade with an XAO loop. In addition, it may prove useful for imaging fainter or lighter close-in companions. In more challenging conditions, contrast improvements are also achieved by adjusting the control loop features. Our study validates the ZWFS-based second-stage AO loop as an effective solution to address small residuals left from a single-stage XAO system for the coronagraphic observations of circumstellar environments.

Figures

Figures reproduced from arXiv: 2411.11946 by the authors.

Figure 1
Figure 1. Presentation of the GHOST testbed. Left: Optical layout of the GHOST bench, with the following symbols: L: lens, BS: beam splitter, DM: deformable mirror, SLM: spatial light modulator. See text for more details. The modulation mirror used for the PWFS and located between BS3 and Lw f s1 is not represented in this scheme. Right: Picture of the testbed on March 8, 2023. fiber, a point-like source emits a light beam wh… view at source ↗
Figure 2
Figure 2. Schematic diagram of the ZWFS analysis with the wavefront errors in the entrance pupil to be estimated, a phase-shifting mask cen￾tered on the on-axis stellar point source at the focus of the telescope aperture and the intensity measurement in the relayed pupil plane. In the small aberration regime (φ ≪ 1 rad), a linear reconstruction of the aberrations is performed from the recorded intensity with a nanometric accu… view at source ↗
Figure 3
Figure 3. Temporal evolution of the wavefront errors. Top: Evolution for a few single modes. For each mode, the wavefront errors have been artificially shifted along the vertical axis to enhance readability: all of them actually oscillate around zero in closed loop. Bottom: Evolution for the total amount. In both panels, the dashed vertical line delimits the transition from open (left) to closed loop (right). across the pupil… view at source ↗
Figures from the paper (6 more)
Figure 4
Figure 4. Figure 4: shows the temporal standard deviation σ of the wavefront errors for each mode before and after closing the loop in top plot and the effective gain in the bottom plot. Our ZWFS￾based second stage AO loop reduces the wavefront errors by at least a factor of 5 for all the…
Figure 5
Figure 5. Figure 5: Temporal PSD of the wavefront errors with the ZWFS-based wavefront control and displayed in [PITH_FULL_IMAGE:figures/full_fig_p006_5.png]
Figure 6
Figure 6. Figure 6: Contrast in the coronagraphic images with the ZWFS-based wavefront control. Top: Left and right, frames in log scale before and after closing the ZWFS control loop. The AO residuals based on VLT/SPHERE characteristics with a 6-mag natural guide star and me￾dian observi…
Figure 7
Figure 7. Figure 7: Contrast in the coronagraphic images with the ZWFS control loop for different wind speed conditions. Top: Normalized azimuthal averaged intensity profile of the coronagraphic images produced with the ZWFS wavefront control in open loop (dashed line) and closed loop (so…
Figure 9
Figure 9. Figure 9: Contrast in the coronagraphic images with the ZWFS control loop for different source flux. Top: Normalized azimuthal averaged in￾tensity profile of the coronagraphic images produced with the ZWFS wavefront control in open loop (dashed line) and closed loop (solid line)…
Figure 11
Figure 11. Figure 11: Contrast in the coronagraphic images with the ZWFS and PWFS control loops for low source flux conditions. Top: Normalized azimuthal averaged intensity profile of the coronagraphic images pro￾duced for the control loop with the ZWFS (purple) and the PWFS (red) in open …

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Works this paper leans on

73 extracted references · 54 canonical work pages

  1. [1]

    2021, in Society of Photo-Optical Instru- mentation Engineers (SPIE) Conference Series, V ol

    Ahn, K., Guyon, O., Lozi, J., et al. 2021, in Society of Photo-Optical Instru- mentation Engineers (SPIE) Conference Series, V ol. 11823, Techniques and Instrumentation for Detection of Exoplanets X, ed. S. B. Shaklan & G. J. Ruane, 1182303

    work page 2021

  2. [2]

    P., Bendek, E., Monacelli, B., et al

    Bailey, V . P., Bendek, E., Monacelli, B., et al. 2023, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, V ol. 12680, Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, 126800T

    work page 2023

  3. [3]

    L., Vigan, A., Mouillet, D., et al

    Beuzit, J. L., Vigan, A., Mouillet, D., et al. 2019, A&A, 631, A155

    2019

  4. [4]

    Bloemhof, E. E. & Wallace, J. K. 2003, in SPIE, V ol. 5169, 309–320

    work page 2003

  5. [5]

    2020, arXiv e-prints, arXiv:2003.05714

    Boccaletti, A., Chauvin, G., Mouillet, D., et al. 2020, arXiv e-prints, arXiv:2003.05714

    arXiv 2020

  6. [6]

    2022, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, V ol

    Boccaletti, A., Chauvin, G., Wildi, F., et al. 2022, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, V ol. 12184, Ground- based and Airborne Instrumentation for Astronomy IX, ed. C. J. Evans, J. J. Bryant, & K. Motohara, 121841S

    work page 2022

  7. [7]

    P., Vievard, S., Wilby, M

    Bos, S. P., Vievard, S., Wilby, M. J., et al. 2020, A&A, 639, A52

    2020

  8. [8]

    2019, The Mes- senger, 176, 25

    Cantalloube, F., Dohlen, K., Milli, J., Brandner, W., & Vigan, A. 2019, The Mes- senger, 176, 25

    2019

Show all 73 references
  1. [9]

    Cantalloube, F., Farley, O. J. D., Milli, J., et al. 2020, A&A, 638, A98

    2020

  2. [10]

    H., Dohlen, K., et al

    Cantalloube, F., Por, E. H., Dohlen, K., et al. 2018, A&A, 620, L10

    2018

  3. [11]

    L., Hinkley, S., Bonavita, M., et al

    Carter, A. L., Hinkley, S., Bonavita, M., et al. 2021, MNRAS, 501, 1999

    2021

  4. [12]

    2022, Journal of Astronomical Telescopes, Instruments, and Systems, 8, 019001

    Cerpa-Urra, N., Kasper, M., Kulcsár, C., Raynaud, H.-F., & Taïssir Heritier, C. 2022, Journal of Astronomical Telescopes, Instruments, and Systems, 8, 019001

    2022

  5. [13]

    F., et al

    Chambouleyron, V ., Fauvarque, O., Sauvage, J. F., et al. 2021, A&A, 650, L8

    2021

  6. [14]

    2024, Comptes Rendus Physique, 24, 139

    Chauvin, G. 2024, Comptes Rendus Physique, 24, 139

    2024

  7. [15]

    2022, in Society of Photo- Optical Instrumentation Engineers (SPIE) Conference Series, V ol

    Chilcote, J., Konopacky, Q., Fitzsimmons, J., et al. 2022, in Society of Photo- Optical Instrumentation Engineers (SPIE) Conference Series, V ol. 12184, Ground-based and Airborne Instrumentation for Astronomy IX, ed. C. J

    2022

  8. [16]

    2023, in Adaptive Optics for Extremely Large Telescopes 7th Edition, ONERA, Avignon, France

    Cisse, M., Muslimov, E., Taissir Heritier, C., et al. 2023, in Adaptive Optics for Extremely Large Telescopes 7th Edition, ONERA, Avignon, France

    2023

  9. [17]

    2023, in Astronomical Society of the Pacific Conference Series, V ol

    Currie, T., Biller, B., Lagrange, A., et al. 2023, in Astronomical Society of the Pacific Conference Series, V ol. 534, Protostars and Planets VII, ed. S. Inut- suka, Y . Aikawa, T. Muto, K. Tomida, & M. Tamura, 799

    2023

  10. [18]

    H., Ren, B., & Schneider, G

    Debes, J. H., Ren, B., & Schneider, G. 2019, Journal of Astronomical Telescopes, Instruments, and Systems, 5, 035003

    2019

  11. [19]

    S., Fagginger Auer, F., Escuti, M

    Doelman, D. S., Fagginger Auer, F., Escuti, M. J., & Snik, F. 2019, Optics Let- ters, 44, 17

    2019

  12. [20]

    2004, in EAS Publications Series, ed

    Dohlen, K. 2004, in EAS Publications Series, ed. C. Aime & R. Soummer, V ol. 12, 33–44

    2004

  13. [21]

    2006, in SPIE, V ol

    Dohlen, K., Langlois, M., Lanzoni, P., et al. 2006, in SPIE, V ol. 6267

    2006

  14. [22]

    2022, in 2022 IEEE Workshop on Signal Processing Systems (SiPS), 1–6

    Ferreira, F., Bernard, J., Sevin, A., Doucet, N., & Gratadour, D. 2022, in 2022 IEEE Workshop on Signal Processing Systems (SiPS), 1–6

    2022

  15. [23]

    P., Sallum, S., Millar-Blanchaer, M

    Fitzgerald, M. P., Sallum, S., Millar-Blanchaer, M. A., et al. 2022, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, V ol. 12184, Ground-based and Airborne Instrumentation for Astronomy IX, ed. C. J. Evans, J. J. Bryant, & K. Motohara, 1218426 A...

    2022

  16. [24]

    2006, Optics Express, 14, 7515

    Fusco, T., Rousset, G., Sauvage, J.-F., et al. 2006, Optics Express, 14, 7515

    2006

  17. [25]

    F., Mouillet, D., et al

    Fusco, T., Sauvage, J. F., Mouillet, D., et al. 2016, in Society of Photo-Optical In- strumentation Engineers (SPIE) Conference Series, V ol. 9909, Adaptive Op- tics Systems V , ed. E. Marchetti, L. M. Close, & J.-P. Véran, 99090U

    2016

  18. [26]

    & Mazoyer, J

    Galicher, R. & Mazoyer, J. 2024, Comptes Rendus Physique, 24, 133

    2024

  19. [27]

    S., Seager, S., Mennesson, B., et al

    Gaudi, B. S., Seager, S., Mennesson, B., et al. 2020, arXiv e-prints, arXiv:2001.06683

    2020 arXiv

  20. [28]

    2018, ARA&A, 56, 315

    Guyon, O. 2018, ARA&A, 56, 315

    2018

  21. [29]

    A., Kuchner, M

    Guyon, O., Pluzhnik, E. A., Kuchner, M. J., Collins, B., & Ridgway, S. T. 2006, ApJS, 167, 81

    2006

  22. [30]

    2023, in Adaptive Optics for Extremely Large Telescopes (AO4ELT7), 79

    Haffert, S., Males, J., & Guyon, O. 2023, in Adaptive Optics for Extremely Large Telescopes (AO4ELT7), 79

    2023

  23. [31]

    Haffert, S. Y . 2024, A&A, 683, A113

    2024

  24. [32]

    T., Verinaud, C., & Correia, C

    Heritier, C. T., Verinaud, C., & Correia, C. M. 2023, in Adaptive Optics for Extremely Large Telescopes 7th Edition, ONERA, Avignon, France

    2023

  25. [33]

    L., Ray, S., et al

    Hinkley, S., Carter, A. L., Ray, S., et al. 2022, PASP, 134, 095003

    2022

  26. [34]

    2017, A&A, 603, A23

    Janin-Potiron, P., N’Diaye, M., Martinez, P., et al. 2017, A&A, 603, A23

    2017

  27. [35]

    K., & Serabyn, E

    Jensen-Clem, R., Wallace, J. K., & Serabyn, E. 2012, in 2012 IEEE Aerospace Conference, 1–7

    2012

  28. [36]

    R., Bond, C

    Jovanovic, N., Delorme, J. R., Bond, C. Z., et al. 2019, in Techniques and In- strumentation for Detection of Exoplanets IX, ed. S. B. Shaklan, V ol. 11117, International Society for Optics and Photonics (SPIE), 111170T

    2019

  29. [37]

    2015, PASP, 127, 890

    Jovanovic, N., Martinache, F., Guyon, O., et al. 2015, PASP, 127, 890

    2015

  30. [38]

    2021, The Messenger, 182, 38

    Kasper, M., Cerpa Urra, N., Pathak, P., et al. 2021, The Messenger, 182, 38

    2021

  31. [39]

    P., et al

    Kasper, M., Fedrigo, E., Looze, D. P., et al. 2004, Journal of the Optical Society of America A, 21, 1004

    2004

  32. [40]

    2023, in Adaptive Optics for Extremely Large Telescopes (AO4ELT7), 61

    Kautz, M., Males, J., Close, L., et al. 2023, in Adaptive Optics for Extremely Large Telescopes (AO4ELT7), 61

    2023

  33. [41]

    U., Korkiakoski, V ., Doelman, N., et al

    Keller, C. U., Korkiakoski, V ., Doelman, N., et al. 2012, in Society of Photo- Optical Instrumentation Engineers (SPIE) Conference Series, V ol. 8447, Adaptive Optics Systems III, ed. B. L. Ellerbroek, E. Marchetti, & J.-P. Véran, 844721

    2012

  34. [42]

    U., Doelman, N., et al

    Korkiakoski, V ., Keller, C. U., Doelman, N., et al. 2014, Appl. Opt., 53, 4565

    2014

  35. [43]

    Y ., Males, J

    Landman, R., Haffert, S. Y ., Males, J. R., et al. 2024, A&A, 684, A114

    2024

  36. [44]

    1932, Zeitschrift fur Astrophysik, 5, 73

    Lyot, B. 1932, Zeitschrift fur Astrophysik, 5, 73

    1932

  37. [45]

    R., Ingraham, P., et al

    Macintosh, B., Graham, J. R., Ingraham, P., et al. 2014, Proceedings of the Na- tional Academy of Science, 111, 12661

    2014

  38. [46]

    R., Close, L

    Males, J. R., Close, L. M., Ha ffert, S., et al. 2022, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, V ol. 12185, Adaptive Optics Systems VIII, ed. L. Schreiber, D. Schmidt, & E. Vernet, 1218509

    2022

  39. [47]

    Males, J. R. & Guyon, O. 2018, Journal of Astronomical Telescopes, Instru- ments, and Systems, 4, 019001

    2018

  40. [48]

    2016, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, V ol

    Mawet, D., Wizinowich, P., Dekany, R., et al. 2016, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, V ol. 9909, Adaptive Optics Systems V , ed. E. Marchetti, L. M. Close, & J.-P. Véran, 99090D

    2016

  41. [49]

    2018, in Society of Photo-Optical Instru- mentation Engineers (SPIE) Conference Series, V ol

    Milli, J., Kasper, M., Bourget, P., et al. 2018, in Society of Photo-Optical Instru- mentation Engineers (SPIE) Conference Series, V ol. 10703, Adaptive Optics Systems VI, ed. L. M. Close, L. Schreiber, & D. Schmidt, 107032A N’Diaye, M., Dohlen, K., Cuevas, S., et al. 2010, A&...

    2018

  42. [50]

    2024, Journal of Astronomical Tele- scopes, Instruments, and Systems, 10, 019001

    Nousiainen, J., Engler, B., Kasper, M., et al. 2024, Journal of Astronomical Tele- scopes, Instruments, and Systems, 10, 019001

    2024

  43. [51]

    Oppenheimer, B. R. & Hinkley, S. 2009, ARA&A, 47, 253

    2009

  44. [52]

    Graham, J. R. 2003, ApJ, 596, 702

    2003

  45. [53]

    H., et al

    Pourcelot, R., N’Diaye, M., Por, E. H., et al. 2022, A&A, 663, A49

    2022

  46. [54]

    H., N’Diaye, M., et al

    Pourcelot, R., Por, E. H., N’Diaye, M., et al. 2023, A&A, 672, A73

    2023

  47. [55]

    2021, A&A, 649, A170

    Pourcelot, R., Vigan, A., Dohlen, K., et al. 2021, A&A, 649, A170

    2021

  48. [56]

    Poyneer, L. A. & Macintosh, B. 2004, Journal of the Optical Society of America A, 21, 810

    2004

  49. [57]

    A., Macintosh, B

    Poyneer, L. A., Macintosh, B. A., & Véran, J.-P. 2007, Journal of the Optical Society of America A, 24, 2645

    2007

  50. [58]

    1996, Journal of Modern Optics, 43, 289

    Ragazzoni, R. 1996, Journal of Modern Optics, 43, 289

    1996

  51. [59]

    2018, in Society of Photo-Optical In- strumentation Engineers (SPIE) Conference Series, V ol

    Ruane, G., Riggs, A., Mazoyer, J., et al. 2018, in Society of Photo-Optical In- strumentation Engineers (SPIE) Conference Series, V ol. 10698, Space Tele- scopes and Instrumentation 2018: Optical, Infrared, and Millimeter Wave, ed. M. Lystrup, H. A. MacEwen, G. G. Fazio, N. Ba...

    2018

  52. [60]

    K., Steeves, J., et al

    Ruane, G., Wallace, J. K., Steeves, J., et al. 2020, Journal of Astronomical Tele- scopes, Instruments, and Systems, 6, 045005

    2020

  53. [61]

    2024, ApJ, 967, 171

    Salama, M., Guthery, C., Chambouleyron, V ., et al. 2024, ApJ, 967, 171

    2024

  54. [62]

    2016, in Proc

    Sauvage, J.-F., Fusco, T., Lamb, M., et al. 2016, in Proc. SPIE, V ol. 9909, So- ciety of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, 990916

    2016

  55. [63]

    2016, Journal of Astronomical Tele- scopes, Instruments, and Systems, 2, 011021

    Shi, F., Balasubramanian, K., Hein, R., et al. 2016, Journal of Astronomical Tele- scopes, Instruments, and Systems, 2, 011021

    2016

  56. [64]

    K., Kettenbeil, C., & Jewell, J

    Steeves, J., Wallace, J. K., Kettenbeil, C., & Jewell, J. 2020, Optica, 7, 1267

    2020

  57. [65]

    2010, Appl

    Surdej, I., Yaitskova, N., & Gonte, F. 2010, Appl. Opt., 49, 4052 The LUVOIR Team. 2019, arXiv e-prints, arXiv:1912.06219

    2010 arXiv

  58. [66]

    Traub, W. A. & Oppenheimer, B. R. 2010, Direct Imaging of Exoplanets (Seager, S.), 111–156 van Kooten, M. A. M., Ragland, S., Jensen-Clem, R., et al. 2022, ApJ, 932, 109

    2010

  59. [67]

    2011, Appl

    Vigan, A., Dohlen, K., & Mazzanti, S. 2011, Appl. Opt., 50, 2708

    2011

  60. [68]

    2022, A&A, 660, A140

    Vigan, A., Dohlen, K., N’Diaye, M., et al. 2022, A&A, 660, A140

    2022

  61. [69]

    2019, A&A, 629, A11

    Vigan, A., N’Diaye, M., Dohlen, K., et al. 2019, A&A, 629, A11

    2019

  62. [70]

    & Smith, B

    Vilas, F. & Smith, B. A. 1987, Appl. Opt., 26, 664

    1987

  63. [71]

    K., Rao, S., Jensen-Clem, R

    Wallace, J. K., Rao, S., Jensen-Clem, R. M., & Serabyn, G. 2011, in Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, V ol. 8126

    2011

  64. [72]

    J., Keller, C

    Wilby, M. J., Keller, C. U., Sauvage, J. F., et al. 2018, A&A, 615, A34

    2018

  65. [73]

    1934, MNRAS, 94, 377 Article number, page 12 of 15 M

    Zernike, F. 1934, MNRAS, 94, 377 Article number, page 12 of 15 M. N’Diaye et al.: Cascade adaptive optics with a second stage based on a Zernike wavefront sensor for exoplanet observations Appendix A: Impact of the control loop features We investigate the contrast performance ...

    1934

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