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The aberrations in an optical microscope are commonly measured and corrected at one location in the field of view, within the so-called isoplanatic patch. Full-field correction is desirable for high-resolution imaging of large specimens.…

Optics · Physics 2021-06-04 Daniele Ancora , Tommaso Furieri , Stefano Bonora , Andrea Bassi

Optical aberrations prevent telescopes from reaching their theoretical diffraction limit. Once estimated, these aberrations can be compensated for using deformable mirrors in a closed loop. Focal plane wavefront sensing enables the…

Adaptive optics (AO) is a powerful image correction technique with proven benefits for many life-science microscopy methods. However, the complexity of adding a reflective wavefront modulator and a wavefront sensor into already complicated…

In astronomy or biological imaging, refractive index inhomogeneities of e.g. atmosphere or tissues induce optical aberrations which degrade the desired information hidden behind the medium. A standard approach consists in measuring these…

Optics · Physics 2023-06-01 Tengfei Wu , Marc Guillon , Gilles Tessier , Pascal Berto

In astronomy and microscopy, distortions in the wavefront affect the dynamic range of a high contrast imaging system. These aberrations are either imposed by a turbulent medium such as the atmosphere, by static or thermal aberrations in the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Benjamin Pope , Nick Cvetojevic , Anthony Cheetham , Frantz Martinache , Barnaby Norris , Peter Tuthill

Direct imaging of exoplanets requires very high contrast levels, which are obtained using coronagraphs. But residual quasi-static aberrations create speckles in the focal plane downstream of the coronagraph which mask the planet. This…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 J. Mazoyer , P. Baudoz , R. Galicher , M. Mas , G. Rousset

We present the research status of a deformable mirror made of a magnetic liquid whose surface is actuated by a triangular array of small current carrying coils. We demonstrate that the mirror can correct a 11 microns low order aberrated…

Astronomical adaptive optics systems with open-loop deformable mirror control have recently come on-line. In these systems, the deformable mirror surface is not included in the wavefront sensor paths, and so changes made to the deformable…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Alastair Basden , Richard Myers , Eric Gendron

Multi-photon microscopy is a powerful technique for deep-tissue imaging, providing high spatial resolution at increased penetration depth. Nevertheless, imaging remains largely restricted to superficial tissue layers well below 1 mm.…

We present a promising approach to the extremely fast sensing and correction of small wavefront errors in adaptive optics systems. As our algorithm's computational complexity is roughly proportional to the number of actuators, it is…

Instrumentation and Methods for Astrophysics · Physics 2016-11-26 Christoph U. Keller , Visa Korkiakoski , Niek Doelman , Rufus Fraanje , Raluca Andrei , Michel Verhaegen

The spatial resolution of images of living samples obtained by fluorescence microscopes is physically limited due to the diffraction of visible light, which makes the study of entities of size less than the diffraction barrier (around 200…

Image and Video Processing · Electrical Eng. & Systems 2023-03-21 Vasiliki Stergiopoulou , Subhadip Mukherjee , Luca Calatroni , Laure Blanc-Féraud

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 2017-10-12 Johan Mazoyer , Laurent Pueyo

Achieving atomic resolution in electron microscopy has historically been hindered by spherical aberration, a fundamental limitation of conventional electron lenses. Its correction typically requires complex assemblies of electromagnetic…

Wavefront aberrations are identified as a major limitation in quantum sensors. They are today the main contribution in the uncertainty budget of best cold atom interferometers based on two-photon laser beam splitters, and constitute an…

Atomic Physics · Physics 2017-04-25 Azer Trimeche , Mehdi Langlois , Sébastien Merlet , Franck Pereira dos Santos

Precise alignment of the electron beam is critical for successful application of scanning transmission electron microscopes (STEM) to understanding materials at atomic level. Despite the success of aberration correctors, aberration…

Optical beams and starlight distorted by atmospheric turbulence can be corrected with adaptive optics systems to enable efficient coupling into single-mode fibers. Deformable mirrors, used to flatten the wavefront in astronomical…

Bessel beams generated with non-ideal axicons are affected by aberrations. We introduce a method to retrieve the complex amplitude of a Bessel beam from intensity measurements alone, and then use this information to correct the wavefront…

Optics · Physics 2022-04-06 B. Miao , L. Feder , J. E. Shrock , H. M. Milchberg

We present a liquid crystal method of correcting the phase of an aberrated wavefront using a spatial light modulator. A simple and efficient lab model has been demonstrated for wavefront correction. The crux of a wavefront correcting system…

Instrumentation and Methods for Astrophysics · Physics 2009-10-11 Akondi Vyas , M. B. Roopashree , Ravinder Kumar Banyal , B. Raghavendra Prasad

High quality imaging usually requires bulky and expensive lenses to compensate geometric and chromatic aberrations. This poses high constraints on the optical hash or low cost applications. Although one can utilize algorithmic…

Image and Video Processing · Electrical Eng. & Systems 2021-08-20 Xiu Li , Jinli Suo , Weihang Zhang , Xin Yuan , Qionghai Dai

Wavefront-shaping is a promising approach for imaging fluorescent targets deep inside scattering tissue despite strong aberrations. It enables focusing an incoming illumination into a single spot inside tissue, as well as correcting the…

Optics · Physics 2024-01-23 Dror Aizik , Anat Levin
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