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The correction of the influence of phase corrugation in the pupil plane is a fundamental issue in achieving high dynamic range imaging. In this paper, we investigate an instrumental setup which consists in applying interferometric…

Astrophysics · Physics 2008-11-26 S. Lacour , E. Thiébaut , G. Perrin

Current and future high contrast imaging instruments aim to detect exoplanets at closer orbital separations, lower masses, and/or older ages than their predecessors. However, continually evolving speckles in the coronagraphic science image…

Instrumentation and Methods for Astrophysics · Physics 2022-06-22 Benjamin L. Gerard , Daren Dillon , Sylvain Cetre , Rebecca Jensen-Clem

Diffractive lenses have recently been applied to the domain of multispectral imaging in the X-ray and UV regimes where they can achieve very high resolution as compared to reflective and refractive optics. Conventionally, spectral…

Image and Video Processing · Electrical Eng. & Systems 2020-05-26 Evan Widloski , Ulas Kamaci , Farzad Kamalabadi

We investigate methods to calibrate the non-common path aberrations at an adaptive optics system having a wavefront-correcting device working at an extremely high resolution (larger than 150x150). We use focal-plane images collected…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Visa Korkiakoski , Christoph U. Keller , Niek Doelman , Matthew Kenworthy , Gilles Otten , Michel Verhaegen

We propose a new approach for high-contrast imaging at the diffraction limit using segmented telescopes in a modest observation bandwidth. This concept, named "spectroscopic fourth-order coronagraphy", is based on a fourth-order coronagraph…

Instrumentation and Methods for Astrophysics · Physics 2021-03-17 Taro Matsuo , Satoshi Itoh , Yuji Ikeda

Coronagraphic imaging of exoplanets using ground-based instruments on large telescopes is intrinsically limited by speckles induced by uncorrected aberrations. These aberrations originate from the imperfect correction of the atmosphere by…

Instrumentation and Methods for Astrophysics · Physics 2022-05-04 A. Vigan , K. Dohlen , M. N'Diaye , F. Cantalloube , J. Girard , J. Milli , J. -F. Sauvage , Z. Wahhaj , G. Zins , J. -L. Beuzit , A. Caillat , A. Costille , J. Le Merrer , D. Mouillet , S. Tourenq

The ill-posed problem of phase retrieval in optics, using one or more intensity measurements, has a multitude of applications using electromagnetic or matter waves. Many phase retrieval algorithms are computed on pixel arrays using discrete…

Image and Video Processing · Electrical Eng. & Systems 2022-09-21 J. A. Pollock , K. S. Morgan , L. C. P. Croton , M. K. Croughan , G. Ruben , N. Yagi , H. Sekiguchi , M. J. Kitchen

We propose a solution to the problem of astrometric and photometric calibration of coronagraphic images with a simple optical device which, in theory, is easy to use. Our design uses the Fraunhofer approximation of Fourier optics. Placing a…

Astrophysics · Physics 2008-11-26 Anand Sivaramakrishnan , Ben R. Oppenheimer

Difference imaging is a technique for obtaining precise relative photometry of variable sources in crowded stellar fields and, as such, constitutes a crucial part of the data reduction pipeline in surveys for microlensing events or…

Astrophysics · Physics 2009-11-11 Holger Israel , Frederic V. Hessman , Sonja Schuh

Intensive reverberation mapping monitoring programs combine ground-based photometric observations from different telescopes, requiring intercalibration of lightcurves to reduce systematic instrumental differences. We present a new iterative…

Instrumentation and Methods for Astrophysics · Physics 2025-06-02 Roberta Vieliute , Juan V. Hernández Santisteban , Keith Horne , Hannah Cornfield

Large-scale astronomical surveys can capture numerous images of celestial objects, including galaxies and nebulae. Analysing and processing these images can reveal intricate internal structures of these objects, allowing researchers to…

Instrumentation and Methods for Astrophysics · Physics 2023-11-02 Peng Jia , Jiameng Lv , Runyu Ning , Yu Song , Nan Li , Kaifan Ji , Chenzhou Cui , Shanshan Li

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 instruments will soon be equipped with focal plane wavefront…

In high-contrast space-based coronagraphs, one of the main limiting factors for imaging the dimmest exoplanets is the time varying nature of the residual starlight (speckles). Modern methods try to differentiate between the intensities of…

Instrumentation and Methods for Astrophysics · Physics 2019-09-04 Leonid Pogorelyuk , N. Jeremy Kasdin , Clarence W. Rowley

Angular filter refractometry is an optical diagnostic that measures absolute contours of line-integrated density gradient by placing a filter with alternating opaque and transparent zones in the focal plane of a probe beam, which produce…

Plasma Physics · Physics 2023-11-30 P. V. Heuer , D. Haberberger , S. T. Ivancic , C. A. Walsh , J. R. Davies

The Gemini Planet Imager (GPI) is a next-generation, facility instrument currently being commissioned at the Gemini South observatory. GPI combines an extreme adaptive optics system and integral field spectrograph (IFS) with an…

One of the science drivers for the extremely large telescope (ELT) is imaging and spectroscopy of exo-solar planets located as close as 20mas to their parent star. The application requires a well thought-out design of the high contrast…

Astrophysics · Physics 2009-11-11 Natalia Yaitskova

Direct imaging and spectral characterization of exoplanets using extreme adaptive optics (ExAO) is a key science goal of future extremely large telescopes and space observatories. However, quasi-static wavefront errors will limit the…

Instrumentation and Methods for Astrophysics · Physics 2018-08-29 Benjamin L. Gerard , Christian Marois , Raphaël Galicher

To detect Earth-like planets in the visible with a coronagraphic telescope, two major noise sources have to be overcome: the photon noise of the diffracted star light, and the speckle noise due to the star light scattered by instrumental…

Direct detection and spectroscopy of exoplanets requires high contrast imaging. For habitable exoplanets in particular, located at small angular separation from the host star, it is crucial to employ small inner working angle (IWA)…

Instrumentation and Methods for Astrophysics · Physics 2016-11-09 P. Pathak , O. Guyon , N. Jovanovic , J. Lozi , F. Martinache , Y. Minowa , T. Kudo , H. Takami , Y. Hayano , N. Narita

Optical projection tomography (OPT) is a powerful tool for biomedical studies. It achieves 3D visualization of mesoscopic biological samples with high spatial resolution using conventional tomographic-reconstruction algorithms. However,…

Optics · Physics 2025-02-07 Yan Liu , Jonathan Dong , Thanh-an Pham , François Marelli , Michael Unser