Publications (30)
SUPPPPRESS: Prototyping and testing liquid-crystal vector vortex coronagraphs with reduced polarization leakage
Rico Landman, David Doelman, Jeroen Rietjens +16
The vortex coronagraph is one of the most promising candidates for the Habitable Worlds Observatory (HWO) due to its excellent theoretical performance for an off-axis telescope. A…
Random Vibration Testing of Microelectromechanical Deformable Mirrors for Space-based High-Contrast Imaging
Axel Potier, Camilo Mejia Prada, Garreth Ruane +11
Space-based stellar coronagraph instruments aim to directly image exoplanets that are a fraction of an arcsecond separation and ten billion times fainter than their host star. To a…
First high-contrast results on THD2 testbed after infrastructure upgrade
Iva Laginja, Pierre Baudoz, Rémi Soummer +17
We present the first scientific results delivered by the upgraded THD2 high-contrast imaging testbed. We report two advances enabled by its improved stability and broadband perform…
SAXO+, the second-stage adaptive optics for SPHERE: NCPA compensation and dark-hole loop with a pyramid wavefront sensor
Johan Mazoyer, Charles Goulas, Raphaël Galicher +21
The SAXO+ upgrade of the VLT/SPHERE adaptive optics system introduces a second-stage near-infrared pyramid wavefront sensor to improve high-contrast imaging, making accurate calibr…
Revisiting the Borde-Traub focal plane wavefront estimation technique for exoplanet direct imaging
Axel Potier, A J Eldorado Riggs, Garreth Ruane +8
Direct imaging of exoplanets relies on complex wavefront sensing and control architectures. In addition to fast adaptive optics systems, most of the future high-contrast imaging in…
Experimental demonstration of spectral linear dark field control at NASA's high contrast imaging testbeds
Phillip K. Poon, Axel Potier, Garreth Ruane +6
Due to the low flux of exoEarths, long exposure times are required to spectrally characterize them. During these long exposures, the contrast in the dark hole will degrade as the t…
Extended Linearity in the High-Order Wavefront Sensor for the Roman Coronagraph
Iva Laginja, Pierre Baudoz, Johan Mazoyer +3
Context. The Coronagraphic Instrument (CGI) on the Roman Space Telescope aims for unprecedented contrast for direct imaging of exoplanets, serving as a critical tech demo for futur…
The Programmable Liquid-crystal Active Coronagraphic Imager for the DAG telescope (PLACID) instrument: On-site status update ahead of first light
Jonas G. Kühn, Laurent Jolissaint, Audrey Baur +8
The Programmable Liquid-crystal Active Coronagraphic Imager for the DAG telescope (PLACID) instrument is a novel high-contrast direct imaging facility that was recently delivered t…
CATKit2-HCI: a collaborative framework for advancing high-contrast coronagraph testbeds
Rémi Soummer, Iva Laginja, Emiel H. Por +19
High-contrast exoplanet imaging requires dedicated laboratory testbeds for the development and validation of coronagraph architectures, wavefront sensing and control methods, calib…
Increasing the raw contrast of VLT/SPHERE with the dark-hole technique. II. On-sky wavefront correction and coherent differential imaging
Axel Potier, Johan Mazoyer, Zahed Wahhaj +4
Context. Direct imaging of exoplanets takes advantage of state-of-the-art adaptive optics (AO) systems, coronagraphy, and post-processing techniques. Coronagraphs attenuate starlig…
Adaptive optics performance of a simulated coronagraph instrument on a large, segmented space telescope in steady state
Axel Potier, Garreth Ruane, Christopher C. Stark +9
Directly imaging Earth-like exoplanets (``exoEarths'') with a coronagraph instrument on a space telescope requires a stable wavefront with optical path differences limited to tens…
Contrast performance of an 8m off-axis, segmented space telescope equipped with an adaptive optics system
Axel Potier, Garreth Ruane, Kiarash Tajdaran +9
The Astro2020 decadal survey recommended an infrared, optical, ultra-violet (IR/O/UV) telescope with a 6~m inscribed diameter and equipped with a coronagraph instrument to di…
Increasing the raw contrast of VLT/SPHERE with the dark hole technique. I. Simulations and validation on the internal source
Axel Potier, Raphaël Galicher, Pierre Baudoz +7
Context. Since 1995 and the first discovery of an exoplanet orbiting a main-sequence star, 4000 exoplanets have been discovered using several techniques. However, only a few of the…
Enhanced wavefront sensing for the Roman Coronagraph Instrument: Gaussian probes and compact model validation
Lukas Delaye, Iva Laginja, Pierre Baudoz +10
The paper evaluates the use of Gaussian probe patterns for focal‑plane wavefront sensing in the Roman Space Telescope's Coronagraph Instrument, showing via simulations that they ca…
Coherence differential imaging using gradient-boosted decision trees for the direct detection of exoplanets
Johan Mazoyer, MarÃa J. Mellado-Tenorioa, MarÃa J. Mellado-Tenorio +5
Coronagraphic imaging of exoplanets is limited by residual speckles that mimic planets. Advanced post-processing is essential for current and future instruments on the ground or in…
Improving VLT/SPHERE without additional hardware: Comparing quasi-static correction strategies
Axel Potier, Zahed Wahhaj, Raphael Galicher +4
Direct imaging is the primary technique currently used to detect young and warm exoplanets and understand their formation scenarios. The extreme flux ratio between an exoplanet and…
Advancing European High-Contrast Imaging R&D Towards the Habitable Worlds Observatory
Iva Laginja, Ãscar Carrión-González, Romain Laugier +31
The Habitable Worlds Observatory (HWO) will enable a transformative leap in the direct imaging and characterization of Earth-like exoplanets. For this, NASA is focusing on early in…
LUVOIR-ECLIPS closed-loop adaptive optics performance and contrast predictions
Axel Potier, Garreth Ruane, Pin Chen +8
One of the primary science goals of the Large UV/Optical/Infrared Surveyor (LUVOIR) mission concept is to detect and characterize Earth-like exoplanets orbiting nearby stars with d…
Active minimization of non-common path aberrations in long-exposure imaging of exoplanetary systems
Garima Singh, Raphaël Galicher, Pierre Baudoz +5
Context. Spectroscopy of exoplanets is very challenging because of the high star-planet contrast. A technical difficulty in the design of imaging instruments is the noncommon path…
Discovery space and science with the PLACID stellar coronagraph
Ruben Tandon, Liurong Lin, Axel Potier +4
The world's first ever ''adaptive stellar coronagraph'' facility will be the PLACID instrument, installed on Turkey's new national observatory 4-m DAG telescope. PLACID incorporate…
Laboratory demonstration of the triple-grating vector vortex coronagraph
David S. Doelman, Mireille Ouellet, Axel Potier +5
The future Habitable Worlds Observatory aims to characterize the atmospheres of rocky exoplanets around solar-type stars. The vector vortex coronagraph (VVC) is a main candidate to…
Laboratory demonstration of the wrapped staircase scalar vortex coronagraph
Niyati Desai, Garreth J. Ruane, Jorge D. Llop-Sayson +5
Of the over 5000 exoplanets that have been detected, only about a dozen have ever been directly imaged. Earth-like exoplanets are on the order of 10 billion times fainter than thei…
Comparative laboratory study of electric field conjugation algorithms
Niyati Desai, Axel Potier, Susan F. Redmond +5
Future space telescope coronagraph instruments hinge on the integration of high-performance masks and precise wavefront sensing and control techniques to create dark holes essentia…
Upgrading SPHERE with the second stage AO system SAXO+: non-common path aberrations estimation and correction
Johan Mazoyer, Charles Goulas, Fabrice Vidal +16
SAXO+ is a planned enhancement of the existing SAXO, the VLT/ SPHERE adaptive optics system, deployed on ESO's Very Large Telescope. This upgrade is designed to significantly enhan…
Increasing the raw contrast of VLT/SPHERE with dark hole techniques III. Broadband reference differential imaging of HR\,4796 using a four-quadrant phase mask
Raphael Galicher, Axel Potier, Johan Mazoyer +3
Imaging exoplanetary systems is essential to characterizing exoplanetary systems and to studying planet-disk interactions to understand planet formation. Such imaging in the visibl…
Continuing to Advance European High Contrast Imaging Research and Development towards HWO and LIFE
Gael Chauvin, Oscar Carrion Gonzalez, Iva Laginja +20
The European Research and Development for Space based High Contrast Imaging II Workshop, held at MPIA in May 2025, advanced Europe strategic coordination in support of future exopl…
Coherent Differential Imaging of high-contrast extended sources with VLT/SPHERE
Axel Potier, Raphaël Galicher, Pierre Baudoz +6
High-contrast imaging relies on advanced coronagraphs and adaptive optics (AO) to attenuate the starlight. However, residual aberrations, especially non-common path aberrations bet…
Future exoplanet direct imaging instruments: Simulating spatial light modulator-based pixelated focal-plane coronagraphy
Liurong Lin, Axel Potier, Ruben Tandon +1
The programmable Liquid-crystal Active Coronagraphic Imager for the DAG Telescope (PLACID) instrument will be installed on the Turkish 4-m Telescope by the fall of 2024 and is expe…
The Programmable Liquid-crystal Active Coronagraphic Imager for the 4-m DAG telescope (PLACID) instrument: installation and commissioning update
Jonas G. Kühn, Ruben Tandon, Lucas Marquis +9
The Programmable Liquid-crystal Active Coronagraphic Imager for the DAG telescope (PLACID) instrument is a novel high-contrast direct imaging facility that was recently installed o…
Comparing focal plane wavefront control techniques:\\Numerical simulations and laboratory experiments
Axel Potier, Pierre Baudoz, Raphaël Galicher +2
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 imag…