A5049612966- Adaptive optics and wavefront sensing
- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Calibration and Measurement Techniques
- Optical Polarization and Ellipsometry
- Advanced optical system design
- Optical Systems and Laser Technology
- Astronomical Observations and Instrumentation
- CCD and CMOS Imaging Sensors
- Astro and Planetary Science
- Advanced Semiconductor Detectors and Materials
- Scientific Research and Discoveries
- Planetary Science and Exploration
- Spectroscopy and Laser Applications
- Optical Coherence Tomography Applications
- Optical Wireless Communication Technologies
- Optical measurement and interference techniques
- Photonic and Optical Devices
- Space Science and Extraterrestrial Life
- Geophysics and Gravity Measurements
- Solar and Space Plasma Dynamics
- Superconducting and THz Device Technology
- Space exploration and regulation
- Optical and Acousto-Optic Technologies
- Digital Holography and Microscopy
Space Telescope Science Institute
2021-2024
Centre National de la Recherche Scientifique
2023
University of Arizona
2023
Laboratoire d’études spatiales et d’instrumentation en astrophysique
2023
Université de Versailles Saint-Quentin-en-Yvelines
2023
Sorbonne Université
2023
Université Paris Cité
2023
Observatoire de Paris
2023
Leiden University
2016-2022
University of California, San Diego
2022
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...
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. The wind-driven halo is a feature that observed in images were delivered by the latest generation of ground-based instruments are equipped with an extreme adaptive optics system and coronagraphic device, such as SPHERE at Very Large Telescope (VLT). This signature appears when atmospheric turbulence conditions vary faster than loop can correct for. radial extension point spread function along distinct direction (this sometimes referred to butterfly pattern). When this present, it...
The latest generation of high contrast instruments dedicated to exoplanets and circumstellar disks imaging are equipped with extreme adaptive optics coronagraphs reach contrasts up 10^--4 at a few tenths arc-seconds in the near infrared. resulting image shows faint features, only revealed this combination, such as wind driven halo. halo is due lag between correction turbulence speed over telescope pupil. However we observe an asymmetry that was not expected when instrument designed. In...
The design of liquid-crystal diffractive phase plate coronagraphs for ground-based and space-based high-contrast imaging systems is limited by the trade-off between spectral bandwidth polarization leakage. We demonstrate that combining patterns with a grating (PG) pattern directly followed one or several separate PGs, we can suppress leakage terms additional orders magnitude diffracting them out beam. Using two PGs composed single-layer liquid crystal structure in lab, suppression more than...
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...
In self-gravitating $N$-body systems, small perturbations introduced at the start, or infinitesimal errors that are produced by numerical integrator due to limited precision in computer, grow exponentially with time. For Newton's gravity, we confirm earlier results for relatively homogeneous this rate of growth per crossing time increases $N$ up $N \sim 30$, but larger has a weaker scaling $N$. concentrated however, exponential continues scale relativistic is almost independent This effect,...
SPHERE (Beuzit et al,. 2019) has now been in operation at the VLT for more than 5 years, demonstrating a high level of performance. produced outstanding results using variety operating modes, primarily field direct imaging exoplanetary systems, focusing on exoplanets as point sources and circumstellar disks extended objects. The achievements obtained thus far with (~200 refereed publications) different areas (exoplanets, disks, solar system, stellar physics...) have motivated large...
The phase-apodized-pupil Lyot coronagraph (PAPLC) is a pairing of the apodized-pupil (APLC) and apodizing phase plate (APP) coronagraph. We describe numerical optimization method to obtain globally-optimal solutions for apodizers arbitrary telescope pupils, based on linear map between complex-amplitude transmission apodizer electric field in post-coronagraphic focal plane. PAPLCs with annular focal-plane masks point-symmetric dark zones perform analogous their corresponding APLCs. However...
Direct observations of exoplanets require a stellar coronagraph to suppress the diffracted starlight. An Apodizing Phase Plate (APP) consists carefully designed phase-only mask in pupil plane telescope. This alters point spread function such way that it contains dark zone at some off-axis region interest, while still retaining high Strehl ratio (and therefore planet throughput). Although many methods for designing phase exist, none them provide guarantee global optimality. Here we present...
We present the monochromatic lab verification of newly developed SCAR coronagraph that combines a phase plate (PP) in pupil with microlens-fed single-mode fiber array focal plane. The two designs have been measured, create respectively 360 degree and 180 dark region from 0.8-2.4 λ/D around star. has designed for clear aperture realistic central obscuration spiders. creates measured stellar null $2-3 \times 10^{-4}$ , reaches $1 . Their contrast is maintained within range $\pm$ 0.16...
The discovery of an Earth-mass exoplanet around the nearby star Proxima Centauri provides a prime target for search life on planets outside our solar system. Atmospheric characterization these has been proposed by blocking starlight with stellar coronagraph and using high-resolution spectrograph to reflected off planet. Due large flux ratio small angular separation between b its host ($\lesssim10^{-7}$ $\lesssim2.2\lambda/D$ respectively; at 750nm 8m-class telescope) needs have high...
We present the final results of Apodized Pupil Lyot Coronagraph (APLC) on High-contrast imager for Complex Aperture Telescopes (HiCAT) testbed, under NASA's Strategic Astrophysics Technology program. The HiCAT testbed was developed over past decade to enable a system-level demonstration coronagraphy exoplanet direct imaging with future Habitable Wolds Observatory. includes an active, segmented telescope simulator, coronagraph, and metrology systems (Low-order Mid-Order Zernike Wavefront...
With the commencement of development Habitable Worlds Observatory, it is imperative that community has an understanding (1) stability requirements for observatory to inform design and (2) gains expected from post-processing observing scenarios science yield estimates. We demonstrate a previously developed, photon-efficient dark zone maintenance (DZM) algorithm corrects quasi-static wavefront error drifts using only images compatible with traditional techniques. Further, we augment DZM...
The direct detection and spectral characterization of exoplanets requires a coronagraph to suppress the diffracted star light. Amplitude phase aberrations in optical train fill dark zone with quasi-static speckles that limit achievable contrast. Focal-plane electric field sensing, such as diversity introduced by deformable mirror (DM), is powerful tool minimize this residual can be estimated sequentially applying probes on DM inject light well-known amplitude into analyzing resulting...
Context. The detection and characterization of Earth-like exoplanets (exoEarths) from space requires exquisite wavefront stability at contrast levels 10 −10 . On segmented telescopes in particular, aberrations induced by co-phasing errors lead to a light leakage through the coronagraph, deteriorating imaging performance. These need be limited order facilitate direct exoEarths. Aims. We perform laboratory validation an analytical tolerancing model that allows us determine error requirements...
The challenges of high contrast imaging (HCI) for detecting exoplanets both ground and space applications can be met with extreme adaptive optics (ExAO), a high-order system that performs wavefront sensing (WFS) correction at speed. We describe 2 ExAO optical designs, one each ground- based telescopes space-based missions, examine them using the angular spectrum Fresnel propagation module within Physical Optics Propagation in Python (POPPY) package. present an end-to-end (E2E) simulation...
The Magellan Extreme Adaptive Optics (MagAO-X) Instrument is an extreme AO system coming online at the end of 2019 that will be operating within visible and near-IR. With state-of-the-art wavefront sensing coronagraphy, MagAO-X optimized for high-contrast direct exoplanet imaging challenging wavelengths, particularly <italic>H</italic>α. To enable imaging, instrument hosts a vector apodizing phase plate (vAPP) coronagraph. vAPP creates static region high contrast next to star referred as...
We present the monochromatic lab verification of newly developed SCAR coronagraph that combines a phase plate (PP) in pupil with microlens-fed single-mode fiber array focal plane. The two designs have been measured, create respectively 360 degree and 180 dark region from 0.8 – 2.4 λ ∕ D around star. has designed for clear aperture realistic central obscuration spiders. creates measured stellar null 2 3 × 10 −4 , reaches 1 . Their contrast is maintained within range ±0.16 peak-to-valley...
The Gemini Planet Imager (GPI) is an integral field spectrograph (IFS) and coronagraph that one of the few current generation instruments optimized for high-contrast direct imaging substellar companions. instrument in process being upgraded moved from its mount on South Observatory Cerro Pach´on, Chile, to twin observatory, North, Mauna Kea (a colloquially dubbed "GPI 2.0"). We present designs have been developed part GPI 2.0 pertains upgrading various optical components coronagraphic...