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Related papers: Interferometric apodization by homothety -- II. Ex…

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Observations at mas-resolution scales and high dynamic range hold a central place in achieving, for instance, the spectroscopic characterization of exo-Earths or the detailed mapping of their protoplanetary disc birthplace. Ground or…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Lucas Labadie , Guillermo Martin , Norman C. Anheier , Brahim Arezki , H. A. Qiao , Bruce Bernacki , Pierre Kern

Stellar coronagraphs designed for high-contrast imaging of exoplanets inevitably introduce a small amount of instrumental polarization, called \emph{secondary polarization}. At the contrast levels required to detect and characterize…

Instrumentation and Methods for Astrophysics · Physics 2025-08-04 Richard A. Frazin

Although a lateral-shear interferometer is robust against optical component vibrations, its interferogram provides information about differential wavefronts rather than the wavefronts themselves, resulting in the loss of specific frequency…

The current generation of ground-based coronagraphic instruments uses deformable mirrors to correct for phase errors and to improve contrast levels at small angular separations. Improving these techniques, several space and ground based…

Instrumentation and Methods for Astrophysics · Physics 2017-10-11 Johan Mazoyer , Laurent Pueyo , Mamadou N'Diaye , Dimitri Mawet , Rémi Soummer , Colin Norman

CONTEXT: The attachment of free electrons to polycondensed aromatic ring molecules (PAHs) is studied for the variety of these molecules with different numbers of condensed rings and over a broad range of electron temperatures, using a…

Astrophysics of Galaxies · Physics 2015-06-05 F. Carelli , T. Grassi , F. A. Gianturco

The direct detection and imaging of exoplanets requires the use of high-contrast adaptive optics (AO). In these systems quasi-static aberrations need to be highly corrected and calibrated. In order to achieve this, the pupil-modulated…

Instrumentation and Methods for Astrophysics · Physics 2022-05-25 Nicolas Dubost , Nazim Ali Bharmal , Marc Dubbeldam , Richard M. Myers

High resolution imaging is achieved using increasingly larger apertures and successively shorter wavelengths. Optical aperture synthesis is an important high-resolution imaging technology used in astronomy. Conventional long baseline…

A Mach-Zehnder interferometer with absorbing Fabry-P\'{e}rot cavities is used to measure the optical phase differences upon rotation around a vertical axis. The details of the expected experimental results are described based on the idea…

Optics · Physics 2015-04-06 Victor-Otto de Haan

This paper introduces a novel wavefront sensing approach that relies on the Fourier analysis of a single conventional direct image. In the high Strehl ratio regime, the relation between the phase measured in the Fourier plane and the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Frantz Martinache

Aperture synthesis instruments providing a generally highly uniform sampling of the visibility function often leave an unsampled hole near the origin of the (u,v)-plane. In this paper, originally published in 1979, we first describe the…

Instrumentation and Methods for Astrophysics · Physics 2017-11-29 R. D. Ekers , A. H. Rots

We have measured the photothermal effect in a single cross-polarized interferometer at audio frequencies (5 Hz - 4 kHz). In a Fabry-Perot interferometer, light in one polarization is chopped to periodically heat the interferometer mirrors,…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Shanti R. Rao

We are aiming to identify the thin insulating inhomogeneities and small conductive inhomogeneities inside an electrically conducting medium by using multi-frequency electrical impedance tomography (mfEIT). The thin insulating…

Analysis of PDEs · Mathematics 2016-08-24 Habib Ammari , Jin Keun Seo , Tingting Zhang

Spatial coherence of light sources is usually obtained by using the classical Youngs interferometer. Despite the original experiment has been improved in successive works, some drawbacks still remain. In addition, several pairs of points…

Optics · Physics 2024-01-17 FJ Torcal-Milla , J Lobera , EM Roche , AM Lopez , V Palero , N Andres , P Arroyo

Acoustic waves in a slightly compressible fluid saturating porous periodic structure are studied using two complementary approaches: 1) the periodic homogenization (PH) method provides effective model equations for a general dynamic problem…

Fluid Dynamics · Physics 2021-01-07 Eduard Rohan , Robert Cimrman

Polarized emission from polycyclic aromatic hydrocarbons (PAHs) potentially provides a new way to test basic physics of the alignment of ultrasmall grains. In this paper, we present a new model of polarized PAH emission that takes into…

Astrophysics of Galaxies · Physics 2017-04-12 Thiem Hoang

Acoustoelectric (AE) imaging provides electro-anatomical contrast by mapping the distribution of electric fields in biological tissues, by delivering ultrasound waves which spatially modulate the medium resistivity via the AE effect. The…

Image and Video Processing · Electrical Eng. & Systems 2025-12-17 Wei Yi Oon , Yuchen Tang , Baiqian Qi , Wei-Ning Lee

We present a statistical interpretation of beamforming to overcome limitations of standard delay-and-sum (DAS) processing. Both the interference and the signal of interest are viewed as random variables and the distribution of the signal of…

Information Theory · Computer Science 2018-06-12 Tanya Chernyakova , Dan Cohen , Meged Shoham , Yonina C. Eldar

Reconstruction of the point spread function (PSF) plays an important role in many areas of astronomy, including photometry, astrometry, galaxy morphology, and shear measurement. The atmospheric and instrumental effects are the two main…

Instrumentation and Methods for Astrophysics · Physics 2024-04-25 Pedro Alonso , Jun Zhang , Cong Liu

Compact interferometers, called phasemeters, make it possible to operate over a large range while ensuring a high resolution. Such performance is required for the stabilization of large instruments dedicated to experimental physics such as…

Instrumentation and Methods for Astrophysics · Physics 2018-12-03 Jennifer Watchi , Sam Cooper , Binlei Ding , Conor M. Mow-Lowry , Christophe Collette

Interstellar Polycyclic Aromatic Hydrocarbon (PAH) molecules exist in diverse forms depending on the local physical environment. Formation of ionized PAHs (anions and cations) is favourable in the extreme conditions of the ISM. Besides in…

Astrophysics of Galaxies · Physics 2017-12-27 Mridusmita Buragohain , Amit Pathak , Peter Sarre , Nand Kishor Gour