High-contrast imaging in polychromatic light with the self-coherent camera

Mazoyer, J.; Baudoz, Pierre; Galicher, R.; Rousset, G.

doi:10.1051/0004-6361/201423375

Cited by 52 publications

(62 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Thus, by applying two numerical Fourier transforms on the recorded image I, the electric field E S 0 of the stellar speckles present in the science image can be estimated (Mazoyer et al 2014a).…”

Section: The Self-coherent Cameramentioning

confidence: 99%

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

Potier

Baudoz

Galicher

et al. 2020

A&A

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Section: The Self-coherent Cameramentioning

confidence: 99%

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

Potier

Baudoz

Galicher

et al. 2020

A&A

Self Cite

View full text Add to dashboard Cite

show abstract

“…Since 1995, several methods have been developed and have proven their efficiency. For a faster correction, most of them separate estimation and control of the wavefront, using complementary sensing methods such as the SelfCoherent Camera (SCC) [21] and the COronagraphic Focal-plane waveFront Estimation for Exoplanet detection (COFFEE) [22]. In this section, we introduce different well-known wavefront control algorithms.…”

Section: Wavefront Sensing and Wavefront Control: The Way To Higmentioning

confidence: 99%

Comparison of wavefront control algorithms and first results on the high-contrast imager for complex aperture telescopes (hicat) testbed

Leboulleux

N’Diaye

Mazoyer

et al. 2017

International Conference on Space Optics — ICSO 2016

Self Cite

View full text Add to dashboard Cite

“…Other focal plane wavefront sensing methods, such as the Self-Coherent Camera technique, can measure the electric field at the science detector and provide significant contrast improvements but require minor modifications to the coronagraphic hardware (Mazoyer et al, 2014).…”

Section: Introductionmentioning

confidence: 99%

Electric field conjugation for ground-based high-contrast imaging: robustness study and tests with the Project 1640 coronagraph

Matthews

2017

J. Astron. Telesc. Instrum. Syst

View full text Add to dashboard Cite

Abstract. The electric field conjugation (EFC) algorithm has shown promise for removing scattered starlight from high-contrast imaging measurements, both in numerical simulations and laboratory experiments. To prepare for the deployment of EFC using ground-based telescopes we investigate the response of EFC to unaccounted for deviations from an ideal optical model. We explore the linear nature of the algorithm by assessing its response to a range of inaccuracies in the optical model generally present in real systems. We find that the algorithm is particularly sensitive to unresponsive deformable mirror (DM) actuators, misalignment of the Lyot stop, and misalignment of the focal plane mask. Vibrations and DM registration appear to be less of a concern compared to values expected at the telescope. We quantify how accurately one must model these core coronagraph components to ensure successful EFC corrections. We conclude that while the condition of the DM can limit contrast, EFC may still be used to improve the sensitivity of high-contrast imaging observations. Our results have informed the development of a full EFC implementation using the Project 1640 coronagraph at Palomar observatory. While focused on a specific instrument our results are applicable to the many coronagraphs that may be interested in employing EFC.

show abstract

High-contrast imaging in polychromatic light with the self-coherent camera

Cited by 52 publications

References 15 publications

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

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

Comparison of wavefront control algorithms and first results on the high-contrast imager for complex aperture telescopes (hicat) testbed

Electric field conjugation for ground-based high-contrast imaging: robustness study and tests with the Project 1640 coronagraph

Contact Info

Product

Resources

About