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Structured light, where complex optical fields are tailored in all their degrees of freedom, has become highly topical of late, advanced by a sophisticated toolkit comprising both linear and nonlinear optics. Removing undesired structure…

We present a reference-free computational wavefront sensor based on binary amplitude modulation and phase retrieval. The method employs Digital Micro-mirror Device as a programmable amplitude modulator and reconstructs the complex optical…

Optics · Physics 2026-02-12 Ondrej Denk , Jan Pilar , Martin Divoky , Miroslav Cech , Tomas Mocek

Optical distortions can significantly deteriorate the measurement accuracy in imaging systems. Such distortions can occur at fluctuating phase boundaries as well as multiple-phase flows and result from the accompanied refractive index…

Applied Physics · Physics 2018-02-21 M. Teich , J. Grottke , H. Radner , L. BÜttner , J. W. Czarske

Modern Giant Segmented Mirror Telescopes (GSMTs) like the Extremely Large Telescope, which is currently under construction, depend heavily on Adaptive Optics (AO) systems to correct for atmospheric distortions. However, a residual blur…

Instrumentation and Methods for Astrophysics · Physics 2023-07-05 Roland Wagner , Jenny Niebsch , Ronny Ramlau

The recent history of optical design saw a progressive trend of also designing without rotational symmetry, especially spectrometers due to the use of reflective and diffractive elements in their designs. A freeform hyperspectral imager…

Optics · Physics 2024-07-10 Yuxuan Liu

Adaptive optics in combination with multi-photon techniques is a powerful approach to image deep into a specimen. Remarkably, virtually all adaptive optics schemes today rely on wavefront modulators which are reflective, diffractive, or…

Shack-Hartmann wavefront sensors for both solar and laser guide star adaptive optics (with elongated spots) need to observe extended objects. Correlation techniques have been successfully employed to measure the wavefront gradient in solar…

Instrumentation and Methods for Astrophysics · Physics 2018-09-11 M. J. Townson , G. D Love , C. D. Saunter

Adaptive optics (AO) systems are crucial for high-resolution astronomical observations by compensating for atmospheric turbulence. While laser guide stars (LGS) address high-order wavefront aberrations, natural guide stars (NGS) remain…

Instrumentation and Methods for Astrophysics · Physics 2024-10-17 Mojtaba Taheri , Mahdiyar Molahasani , Sam Ragland , Benoit Neichel , Peter Wizinowich

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

The search for exoplanets is pushing adaptive optics systems on ground-based telescopes to their limits. One of the major limitations at small angular separations, exactly where exoplanets are predicted to be, is the servo-lag of the…

The use of laser guide stars in astronomical adaptive optics results in elongated Shack-Hartmann wavefront sensor image patterns. Image correlation techniques can be used to determine local wavefront slope by correlating each sub-aperture…

Instrumentation and Methods for Astrophysics · Physics 2014-03-05 Alastair Basden

Several telescopes include large Deformable Mirrors (DM) located directly inside the telescope. These adaptive telescopes trigger new constraints for the calibration of the Adaptive Optics (AO) systems as they usually offer no access to an…

Instrumentation and Methods for Astrophysics · Physics 2019-01-10 C. T. Heritier , S. Esposito , T. Fusco , B. Neichel , S. Oberti , R. Briguglio , G. Agapito , A. Puglisi , E. Pinna , P. -Y. Madec

Astronomical adaptive optics (AO) is a critical approach to enable ground-based diffraction-limited imaging and high contrast science, with the potential to enable habitable exoplanet imaging on future extremely large telescopes. However,…

Instrumentation and Methods for Astrophysics · Physics 2024-06-18 Benjamin L. Gerard , Aaron Lemmer , Bautista R. Fernandez , Xiaoxing Xia , Cesar Laguna , Mike Kim , Stephen Mark Ammons , Brian Bauman , Lisa Poyneer

Atmospheric wavefront prediction based on previous wavefront sensor measurements can greatly enhance the performance of adaptive optics systems. We propose an optimal linear approach based on the Empirical Orthogonal Functions (EOF)…

Instrumentation and Methods for Astrophysics · Physics 2017-07-04 Olivier Guyon , Jared Males

Initially designed to detect and characterize exoplanets, extreme adaptive optics systems (AO) open a new window on the solar system by resolving its small bodies. Nonetheless, despite the always increasing performances of AO systems, the…

Signal Processing · Electrical Eng. & Systems 2024-10-14 Anthony Berdeu , Férréol Soulez , Kate Minker , Benoit Carry , Guillaume Bourdarot , Antoine Kaszczyc , Maud Langlois

Laser guide stars with adaptive optics allow astronomical image correction in the absence of a natural guide star. Single guide star systems with a star created in the earth's sodium layer can be used to correct the wavefront in the near…

Astrophysics · Physics 2009-11-11 S. Rabien , F. Eisenhauer , R. Genzel , R. I. Davies , T. Ott

We demonstrate a novel architecture for Adaptive Optics (AO) control based on FPGAs (Field Programmable Gate Arrays), making active use of their configurable parallel processing capability. SPARC's unique capabilities are demonstrated…

Instrumentation and Methods for Astrophysics · Physics 2018-08-03 Avinash Surendran , Mahesh P. Burse , A. N. Ramaprakash , Jyotirmay Paul , Hillol K. Das , Padmakar S. Parihar

Adaptive optics (AO) restore the angular resolution of ground-based telescopes, but at the cost of delivering a time- and space-varying point spread function (PSF) with a complex shape. PSF knowledge is crucial for breaking existing limits…

Instrumentation and Methods for Astrophysics · Physics 2018-04-17 O. Beltramo-Martin , C. M. Correia , E. Mieda , B. Neichel , T. Fusco , G. Witzel , J. Lu , J. -P. Véran

HWO's Tier 1 Contrast Stability Technology Gap presents a key challenge for technology development in the coming years, requiring to a >100x more stable system than JWST. WaveDriver is a concept for a laser guide star spacecraft coupled to…

Ground-based direct imaging of exoplanets at high contrast requires precise correction of atmospheric turbulence using adaptive optics (AO). The planet-to-star contrast ratio at small angular separations from the host star is often limited…