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Laser guide stars (LGS) are used in many adaptive optics systems to extend sky coverage. The most common wavefront sensor used in combination with a LGS is a Shack-Hartmann wavefront sensor (SHWFS). The Shack-Hartmann has a major…

Instrumentation and Methods for Astrophysics · Physics 2020-12-07 Sebastiaan Y. Haffert , Christoph U. Keller , Richard Dekany

Laser guide star (LGS) wave-front sensing (LGSWFS) is a key element of tomographic adaptive optics system. However, when considering Extremely Large Telescope (ELT) scales, the LGS spot elongation becomes so large that it challenges the…

The advent of spatiotemporal wave packets (STWPs), represented by spatiotemporal optical vortices (STOVs), has paved the way for the exploration in optics and photonics. To date, despite considerable efforts, a comprehensive and efficient…

The TP3-WFS (Two Pupil Plane Positions Wavefront Sensor) is, to the best of the authors' knowledge, the first physical implementation of the geometrical wavefront reconstruction algorithm that has been tested in a telescope as part of an…

The photonic lantern (PL) is a tapered waveguide that can efficiently couple light into multiple single-mode optical fibers. Such devices are currently being considered for a number of tasks, including the coupling of telescopes and…

Instrumentation and Methods for Astrophysics · Physics 2022-09-28 Jonathan Lin , Michael Fitzgerald , Yinzi Xin , Olivier Guyon , Sergio Leon-Saval , Barnaby Norris , Nemanja Jovanovic

The ESA Gaia spacecraft has two Shack-Hartmann wavefront sensors (WFS) on its focal plane. They are required to refocus the telescope in-orbit due to launch settings and gravity release. They require bright stars to provide good signal to…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Alcione Mora , Amir Vosteen

Conventional methods of wavefront reconstruction from the raw data of the Shack-Hartmann sensor use the focal spot shifts and discard the high-frequency information about the wavefront. Phase-retrieval-based methods treat the Hartmann…

Exoplanet imaging has thus far enabled studies of wide-orbit ($>$10 AU) giant planet ($>$2 Jupiter masses) formation and giant planet atmospheres, with future 30 meter-class Extremely Large Telescopes (ELTs) needed to image and characterize…

Instrumentation and Methods for Astrophysics · Physics 2023-08-14 Benjamin L. Gerard , Daren Dillon , Sylvain Cetre , Rebecca Jensen-Clem

The Multiconjugate Adaptive optics Demonstrator (MAD) for ESO-Very Large Telescopes (VLT) will demonstrate on sky the MultiConjugate Adaptive Optics (MCAO) technique. In this paper the laboratory tests relative to the first preliminary…

Instrumentation and Methods for Astrophysics · Physics 2014-11-20 Carmelo Arcidiacono , Matteo Lombini , Emiliano Diolaiti , Jacopo Farinato , Roberto Ragazzoni

In adaptive optics, the measurement of spatial coherence length helps in deciding the optimum design parameters of a Shack Hartmann Sensor (SHS). Two methods of estimating the spatial coherence length of optical wavefronts are presented.…

Instrumentation and Methods for Astrophysics · Physics 2009-11-08 Akondi Vyas , M. B. Roopashree , B. Raghavendra Prasad

In the last few years the concept of an active space telescope has been greatly developed, to meet demanding requirements with a substantial reduction of tolerances, risks and costs. This is the frame of the LATT project (an ESA TRP) and…

Quantum imaging with spatially entangled photons offers advantages such as enhanced spatial resolution, robustness against noise, and counter-intuitive phenomena, while a biphoton spatial aberration generally degrades its performance.…

Quantum Physics · Physics 2025-09-10 Yi Zheng , Zhao-Di Liu , Jian-Shun Tang , Jin-Shi Xu , Chuan-Feng Li , Guang-Can Guo

Wavefront sensing and control (WFSC) will play a key role in improving the stability of future large segmented space telescopes while relaxing the thermo-mechanical constraints on the observatory structure. Coupled with a coronagraph to…

Instrumentation and Methods for Astrophysics · Physics 2023-04-05 R. Pourcelot , E. H. Por , M. N'Diaye , H. Benard , G. Brady , L. Canas , M. Carbillet , K. Dohlen , I. Laginja , J. Lugten , J. Noss , M. D. Perrin , P. Petrone , L. Pueyo , S. F. Redmond , A. Sahoo , A. Vigan , S. D. Will , R. Soummer

The upcoming extremely large telescopes will have to deal with the so-called ''pupil fragmentation'' effect: for what concerns the Extremely Large Telescope (ELT), the presence of thick spider legs supporting the secondary mirror may induce…

Instrumentation and Methods for Astrophysics · Physics 2024-06-05 G. Carlà , L. Busoni , S. Esposito , G. Agapito , R. Holzlöhner

Wavefront sensors are an important tool to characterize coherent beams of extreme ultraviolet radiation. However, conventional Hartmann-type sensors do not allow for independent wavefront characterization of different spectral components…

Instrumentation and Detectors · Physics 2018-04-04 L. Freisem , G. S. M. Jansen , D. Rudolf , K. S. E. Eikema , S. Witte

We consider the mathematical background of the wavefront sensor type that is widely used in Adaptive Optics systems for astronomy, microscopy, and ophthalmology. The theoretical analysis of the pyramid sensor forward operators presented in…

Instrumentation and Methods for Astrophysics · Physics 2019-05-01 Victoria Hutterer , Ronny Ramlau , Iuliia Shatokhina

We describe the concept of splitting spatial frequency perturbations into some kind of pupil planes wavefront sensors. Further to the existing approach of dropping higher spatial frequency to suppress aliasing effects (the so-called spatial…

We demonstrate a wavefront sensor based on the compressive sensing, single-pixel camera. Using a high-resolution spatial light modulator (SLM) as a variable waveplate, we weakly couple an optical field's transverse-position and polarization…

Optics · Physics 2014-07-30 Gregory A. Howland , Daniel J. Lum , John C. Howell

Shack Hartmann wavefront sensor is a two dimensional array of lenslets which is used to detect the incoming phase distorted wavefront through local tilt measurements made by recording the spot pattern near the focal plane. Wavefront…

Instrumentation and Methods for Astrophysics · Physics 2011-08-16 Akondi Vyas , M B Roopashree , B Raghavendra Prasad

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
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