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Ground-based solar observations are severely affected by Earth's turbulent atmosphere. As a consequence, observed image quality and prevailing seeing conditions are closely related. Partial correction of image degradation is nowadays…

Instrumentation and Methods for Astrophysics · Physics 2021-02-10 Robert Kamlah , Meetu Verma , Andrea Diercke , Carsten Denker

The development of adaptive optics (AO) played a major role in modern astronomy over the last three decades. By compensating for the atmospheric turbulence, these systems enable to reach the diffraction limit on large telescopes. In this…

Instrumentation and Methods for Astrophysics · Physics 2017-01-05 Julien Milli , Dimitri Mawet , David Mouillet , Markus Kasper , Julien H. Girard

Control of light through a microscope objective with a high numerical aperture is a common requirement in applications such as optogenetics, adaptive optics, or laser processing. Light propagation, including polarization effects, can be…

Optics · Physics 2023-03-22 Ivan Vishniakou , Johannes D. Seelig

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

Most current astronomical adaptive optics (AO) systems rely on the availability of a bright star to measure the distortion of the incoming wavefront. Replacing the guide star with an artificial laser beacon alleviates this dependency on…

Astrophysics · Physics 2009-11-11 E. Steinbring , S. M. Faber , B. A. Macintosh , D. Gavel , E. L. Gates

All coronagraphic instruments for exoplanet high-contrast imaging need wavefront correction systems to reject optical aberrations and create sufficiently dark holes. Since the most efficient wavefront correction algorithms (controllers and…

Instrumentation and Methods for Astrophysics · Physics 2018-10-09 He Sun , N. Jeremy Kasdin , Robert Vanderbei

We investigate whether a three-mirror system, having secondary and the tertiary mirrors with surfaces warped by Zernike polynomials generated by active vase mirrors, is suitable to do the corrections of a fixed parabolic mirror observing at…

Astrophysics · Physics 2009-10-30 Gilberto Moretto , Ermanno F. Borra

Accurate measurement of polarization in spectral lines is important for the reliable inference of magnetic fields on the Sun. For ground based observations, polarimetric precision is severely limited by the presence of Earth's atmosphere.…

Instrumentation and Detectors · Physics 2012-11-05 K. Nagaraju , Alex Feller

The advent of Wide Field Adaptive Optics (WFAO) systems marks the beginning of a new era in high spatial resolution imaging. The newly commissioned Gemini South Multi-Conjugate Adaptive Optics System (GeMS) combined with the infrared camera…

Instrumentation and Methods for Astrophysics · Physics 2016-11-23 A. Bernard , L. M. Mugnier , B. Neichel , T. Fusco , S. Bounissou , M. Samal , M. Andersen , A. Zavagno , H. Plana

Quantum key distribution (QKD) allows secure key exchange based on the principles of quantum mechanics, with higher-dimensional photonic states offering enhanced channel capacity and resilience to noise. Free-space QKD is crucial for global…

The future large adaptive telescopes will trigger new constraints for the calibration of Adaptive Optics (AO) systems equipped with pre-focal Deformable Mirrors (DM). The image of the DM actuators grid as seen by the Wave-Front Sensor (WFS)…

Instrumentation and Methods for Astrophysics · Physics 2021-05-26 C. T. Heritier , T. Fusco , S. Oberti , B. Neichel , S. Esposito , P. -Y. Madec

We present a new method to achieve high-contrast images using segmented and/or on-axis telescopes. Our approach relies on using two sequential Deformable Mirrors to compensate for the large amplitude excursions in the telescope aperture due…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Laurent Pueyo , Colin Norman

Adaptive optics (AO) has revolutionized imaging in {fields} from astronomy to microscopy by correcting optical aberrations. In label-free microscopes, however, conventional AO faces limitations due to the absence of guidestar and the need…

Ground-based direct imaging surveys like the Gemini Planet Imager Exoplanet Survey (GPIES) rely on Adaptive Optics (AO) systems to image and characterize exoplanets that are up to a million times fainter than their host stars. One factor…

LINC-NIRVANA will realize the interferometric imaging focal station of the Large Binocular Telescope. A double Layer Oriented multi-conjugate adaptive optics system assists the two arms of the interferometer, supplying high order wave-front…

We use spatio-temporal cross-correlations of slopes from five Shack-Hartmann wavefront sensors to analyse the temporal evolution of the atmospheric turbulence layers at different altitudes. The focus is on the verification of the frozen…

Instrumentation and Methods for Astrophysics · Physics 2014-02-28 Andrés Guesalaga , Benoit Neichel , Angela Cortes , Clémentine Béchet , Dani Guzmán

In optical imaging, light propagation is affected by the inhomogeneities of the medium. Sample-induced aberrations and multiple scattering can strongly degrade the image resolution and contrast. Based on a dynamic correction of the incident…

Aberrations limit optical systems in many situations, for example when imaging in biological tissue. Machine learning offers novel ways to improve imaging under such conditions by learning inverse models of aberrations. Learning requires…

Optics · Physics 2021-04-30 Ivan Vishniakou , Johannes D. Seelig

The Astro2020 decadal survey recommended an infrared, optical, ultra-violet (IR/O/UV) telescope with a $\sim$6~m inscribed diameter and equipped with a coronagraph instrument to directly image exoEarths in the habitable zone of their host…

Two-wavelength adaptive optics (AO) systems sense wavefront errors using a beacon at one wavelength, while correcting for subsequent imaging or beam projection at another. Although most AO systems operate in this manner, the relevant AO…

Optics · Physics 2025-09-17 Milo Hyde , Mark Spencer , Matt Kalensky
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