A5081427207- Adaptive optics and wavefront sensing
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Optical Systems and Laser Technology
- Advanced optical system design
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Calibration and Measurement Techniques
- Optical Wireless Communication Technologies
- Gamma-ray bursts and supernovae
- CCD and CMOS Imaging Sensors
- Spectroscopy and Laser Applications
- Photonic and Optical Devices
- Optical measurement and interference techniques
- Meteorological Phenomena and Simulations
- Optical Coatings and Gratings
- Optical Polarization and Ellipsometry
- Scientific Research and Discoveries
- Solar and Space Plasma Dynamics
- Optical Coherence Tomography Applications
- Advanced Measurement and Metrology Techniques
- Photorefractive and Nonlinear Optics
- Inertial Sensor and Navigation
- Economic Growth and Productivity
University of Arizona
2020-2024
Leiden University
2013-2024
Laboratoire d’Astrophysique de Marseille
2023
Aix-Marseille Université
2023
Centre National de la Recherche Scientifique
2023
Space Telescope Science Institute
2023
National Institute for Astrophysics
2022
Astronomical Observatory of Rome
2022
Leiden Observatory
2016-2020
Macquarie University
2020
HCIPy is a package written in Python for simulating the interplay between wavefront control and coronagraphic systems. By defining an element which merges values/coefficients with its sampling grid/modal basis into single object called Field, this minimizes errors writing code makes it clearer to read. provides monochromatic Wavefront defines Propagator that acts as transformation two wavefronts. In way any physical part of optical system, be piece free space, thin complex apodizer or...
Photonics offer numerous functionalities that can be used to realize astrophotonic instruments. The most spectacular example date is the ESO Gravity instrument at Very Large Telescope in Chile. Integrated devices stand critical advantages for development, including extreme miniaturization, as well integration, superior thermal and mechanical stabilization owing small footprint, high replicability offering cost savings. Numerous technologies have been developed address shortcomings of...
Direct imaging of Earth-like planets is one the main science cases for next generation extremely large telescopes. This very challenging due to star-planet contrast that must be overcome. Most current high-contrast instruments are limited in sensitivity at small angular separations non-common path aberrations (NCPA). The NCPA leak through coronagraph and create bright speckles limit on-sky therefore also post-processed contrast. We aim remove by active focal plane wavefront control using a...
ABSTRACT NASA is engaged in planning for a Habitable Worlds Observatory (HabWorlds ), coronagraphic space mission to detect rocky planets habitable zones and establish their habitability. Surface liquid water central the definition of planetary Photometric polarimetric phase curves starlight reflected by an exoplanet can reveal ocean glint, rainbows, other phenomena caused scattering clouds or atmospheric gas. Direct imaging missions are optimized near quadrature, but HabWorlds ’ coronagraph...
Context: Telescopes like the Extremely Large Telescope (ELT) and Giant Magellan (GMT) will be used together with extreme adaptive optics (AO) instruments to directly image Earth-like planets. The AO systems need perform at fundamental limit in order Earth twins. A crucial component is wavefront sensor. Interferometric sensors, such as Zernike sensor (ZWFS), have been shown close sensitivity limit. However, comes cost of linearity; ZWFS has strong nonlinear behavior. Aims: aim this work...
Pyramid wavefront sensors (PWFSs) are the preferred choice for current and future extreme adaptive optics (XAO) systems. Almost all instruments use PWFS in its modulated form to mitigate limited linearity range. However, this modulation comes at cost of a reduction sensitivity, blindness petal-piston modes, limit sensor's ability operate high speeds. Therefore, there is strong interest without modulation, which can be enabled with nonlinear reconstructors. Here, we present first on-sky...
Direct exo-Earth imaging is a key science goal for astronomy in the next decade. This ambitious task imposes target contrast of ~10^-7 at wavelengths from I to J-band. In our prior study, we determined that polarization aberrations can limit achievable 10^-5 10^-6 infrared. However, these results assumed perfect coronagraph coupled telescope with an ideal coating on each mirrors. this study seek understand influence segment-to-segment variations coronagraphy and polarimetry. We use Poke...
Direct exo-earth imaging is a key science goal for astronomy in the next decade. This ambitious task imposes target contrast of ≈ 10^ at wavelengths from I to J-band. In our prior study, we determined that polarization aberrations can limit achievable 10^-5 10^-6 infrared. However, these results assumed perfect coronagraph coupled telescope with an ideal coating on each mirrors. this study seek understand influence segment-to-segment variations coronagraphy and polarimetry. We use Poke...
Understanding the processes of planet formation and accretion in young systems is essential to unraveling initial conditions planetary systems. The PDS 70 system, which hosts two directly imaged protoplanets, provides a unique laboratory for studying these phenomena, particularly through H-alpha emission commonly used tracer. We present multi-epoch observations examine variability signatures within this focusing on b c. Using Hubble Space Telescope narrowband imaging from 2020 2024, we...
Abstract Biosignature detection in the atmospheres of Earth-like exoplanets is one most significant and ambitious goals for astronomy, astrobiology, humanity. Molecular oxygen among strongest indicators life on Earth, but it will be extremely difficult to detect via transmission spectroscopy. We used Bioverse statistical framework assess ability probe O 2 levels hypothetical nearby habitable zone exo-Earth candidates (EECs) using direct imaging high-resolution spectroscopy Giant Magellan...
We investigate the atmosphere of GJ1214b, a transiting super-Earth planet with low mean density, by measuring its transit depth as function wavelength in blue optical portion spectrum. It is thought that this either mini-Neptune, consisting rocky core thick, hydrogen-rich atmosphere, or composition dominated water. Most observations favor water-dominated small scale-height, however, some indicate GJ1214b could have an extended cloud layer muting molecular features. In large Rayleigh...
Context. Accreting planetary-mass objects have been detected at H α , but targeted searches mainly resulted in non-detections. Accretion tracers the regime could originate from shock itself, making them particularly susceptible to extinction by accreting material. High-resolution ( R > 50 000) spectrographs operating should soon enable one study how incoming material shapes line profile. Aims. We calculate much gas and dust onto a planet reduce flux planetary surface they affect shape....
The direct imaging of potentially habitable Exoplanets is one prime science case for the next generation high contrast instruments on ground-based extremely large telescopes. To reach this demanding goal, are equipped with eXtreme Adaptive Optics (XAO) systems which will control thousands actuators at a framerate kilohertz to several kilohertz. Most exoplanets located small angular separations from their host stars, where current XAO systems' laws leave strong residuals.Current AO strategies...
Context. Exoplanet direct imaging is a key science goal of current ground-based telescopes as well future extremely large and space-based telescopes. Several high-contrast (HCI) systems for exoplanet have been developed are implemented on Despite recent developments in HCI systems, the contrast they deliver limited by non-common path aberrations (NCPAs) residual wavefront errors adaptive optics (AO) system. To overcome this limitation reach higher contrast, need focal plane wavefront-sensing...
Fourier-based wavefront sensors, such as the Pyramid Wavefront Sensor (PWFS), are current preference for high contrast imaging due to their sensitivity. However, these sensors have intrinsic nonlinearities that constrain range where conventional linear reconstruction methods can be used accurately estimate incoming aberrations. We propose use Convolutional Neural Networks (CNNs) nonlinear of sensor measurements. It is demonstrated a CNN reconstruct in both simulations and lab implementation....
Over the last decade, vector-apodizing phase plate (vAPP) coronagraph has been developed from concept to on-sky application in many high-contrast imaging systems on 8-m class telescopes. The vAPP is an geometric-phase patterned that inherently broadband, and its manufacturing enabled only by direct-write technology for liquid-crystal patterns. generates two coronagraphic PSFs cancel starlight opposite sides of point spread function (PSF) have circular polarization states. efficiency, amount...
Almost all current and future high-contrast imaging instruments will use a Pyramid wavefront sensor (PWFS) as primary or secondary sensor. The main issue with the PWFS is its nonlinear response to large phase aberrations, especially under strong atmospheric turbulence. Most try increase linearity range by using dynamic modulation, but this leads decreased sensitivity, most prominently for low-order modes, makes it blind petal-piston modes. In push toward of fainter stars deeper contrasts,...
The Optimal Optical Coronagraph (OOC) Workshop held at the Lorentz Center in September 2017 Leiden, Netherlands, gathered a diverse group of 25 researchers working on exoplanet instrumentation to stimulate emergence and sharing new ideas. In this second installment series three papers summarizing outcomes OOC workshop, we present an overview common path wavefront sensing/control Coherent Differential Imaging techniques, highlight latest results, expose their relative strengths weaknesses. We...
Current and future high-contrast imaging instruments require extreme adaptive optics systems to reach contrasts necessary directly imaged exoplanets. Telescope vibrations the temporal error induced by latency of control loop limit performance these systems. One way reduce effects is use predictive control. We describe how model-free reinforcement learning can be used optimize a recurrent neural network controller for closed-loop First, we verify our proposed approach tip–tilt in simulations...
The next generation of Giant Segmented Mirror Telescopes (GSMT) will have large gaps between the segments either caused by shadow mechanical structure secondary mirror [European Extremely Large Telescope (E-ELT) and Thirty Meter (TMT)] or intrinsically design [Giant Magellan (GMT)]. These are enough to fragment aperture into independent that separated more than typical Fried parameter. This creates piston petals modes not well sensed conventional wavefront sensors such as Shack–Hartmann...
GQ Lup B is a young and accreting, substellar companion that appears to drive spiral arm in the circumstellar disk of its host star. We report high-contrast imaging observations with VLT/NACO at 4-5 $\mu$m medium-resolution integral field spectroscopy VLT/MUSE. The optical spectrum consistent an M9 spectral type, shows characteristics low-gravity atmosphere, exhibits strong H$\alpha$ emission. $H-M'$ color $\gtrsim$1 mag redder than dwarfs similar types detailed analysis energy distribution...
Next-generation large segmented mirror telescopes are expected to perform direct imaging and characterization of Earth-like rocky planets, which requires contrast limits $10^{-7}$ $10^{-8}$ at wavelengths from I J band. One critical aspect affecting the raw on-sky polarization aberrations arising reflection telescope's surfaces instrument optics. We simulate estimate their effect on achievable for three next-generation ground-based telescopes. performed ray-tracing in Zemax computed Jones...
The future Habitable Worlds Observatory aims to characterize the atmospheres of rocky exoplanets around solar-type stars. Vector Vortex Coronagraph (VVC) is a main candidate reach required contrast 10<sup>−10</sup>. However, VVC requires polarization filtering and every observing band different VVC. triple-grating vector vortex coronagraph (tgVVC) mitigate these limitations by combining multiple gratings that minimize leakage over large spectral bandwidth. In this paper, we present...