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The Zernike wavefront sensor (ZWFS) stands out as one of the most sensitive optical systems for measuring the phase of an incoming wavefront, reaching photon efficiencies close to the fundamental limit. This quality, combined with the fact…

Future space telescopes with coronagraph instruments will use a wavefront sensor (WFS) to measure and correct for phase errors and stabilize the stellar intensity in high-contrast images. The HabEx and LUVOIR mission concepts baseline a…

Real-time seeing and outer scale estimation at the location of the focus of a telescope is fundamental for the adaptive optics systems dimensioning and performance prediction, as well as for the operational aspects of instruments. This…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Patrice Martinez

Shack Hartmann Sensor (SHS) is inflicted with significant background noise that deteriorates the wave-front reconstruction accuracy. In this paper, a simple method to remove the back ground noise with the use of Zernike polynomials is…

Instrumentation and Methods for Astrophysics · Physics 2011-09-14 Akondi Vyas , M B Roopashree , B Raghavendra Prasad

Continuous wavefront sensing benefits space observatories in on-orbit optical performance maintenance. To measure the phase of a wavefront, phase retrieval is an attractive technique as it uses multiple point spread function (PSF) images…

Instrumentation and Methods for Astrophysics · Physics 2024-09-17 Hyukmo Kang , Kyle Van Gorkom , Meghdoot Biswas , Daewook Kim , Ewan S. Douglas

The correction of quasi-static wavefront errors within a coronagraphic optical system will be a key challenge to overcome in order to directly image exoplanets in reflected light. These quasi-static errors are caused by mid to high-order…

Instrumentation and Methods for Astrophysics · Physics 2024-06-28 Kian Milani , Ewan Douglas , Leonid Pogorelyuk , Christopher Mendillo , Kerri Cahoy , Nicholas Belsten , Brandon Eickert , Shanti Rao

The Thirty Meter Telescope will use a sophisticated adaptive optics system called NFIRAOS. This system utilizes two deformable mirrors conjugate to 0 km and 11.2 km to apply a Multi-Conjugate Adaptive Optics (MCAO) correction over a 2…

Instrumentation and Methods for Astrophysics · Physics 2024-10-17 Mojtaba Taheri , David Andersen , Jean-Pierre Veran , Olivier Lardière

This article describes the implementation of a focal plane based wavefront control loop on the high-contrast imaging instrument SCExAO (Subaru Coronagraphic Extreme Adaptive Optics). The sensor relies on the Fourier analysis of conventional…

Instrumentation and Methods for Astrophysics · Physics 2016-09-07 Frantz Martinache , Nemanja Jovanovic , Olivier Guyon

An important factor which affects performance of solar adaptive optics (AO) systems is the accuracy of tracking an extended object in the wavefront sensor. The accuracy of a centre-ofmass approach to image shift measurement depends on the…

Instrumentation and Methods for Astrophysics · Physics 2015-08-21 M. J. Townson , A. Kellerer , C. D. Saunter

We have designed a plenoptic sensor to retrieve phase and amplitude changes resulting from a laser beam's propagation through atmospheric turbulence. Compared with the commonly restricted domain of (-pi, pi) in phase reconstruction by…

Optics · Physics 2023-07-19 Chensheng Wu , Jonathan Ko , Christopher C. Davis

We present an analytical derivation of the coupling parameter relating the angle between two interfering beams in a heterodyne interferometer to the differential phase-signals detected by a quadrant photo-diode. This technique, also…

Instrumentation and Detectors · Physics 2014-11-21 Gerald Hechenblaikner

Wavefront estimation is an essential component of adaptive optics where the goal is to recover the underlying phase from its Fourier magnitude. While this may sound identical to classical phase retrieval, wavefront estimation faces more…

Signal Processing · Electrical Eng. & Systems 2025-04-15 Nicholas Chimitt , Ali Almuallem , Qi Guo , Stanley H. Chan

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

High performance coronagraphic imaging of faint structures around bright stars at small angular separations requires fine control of tip, tilt and other low order aberrations. When such errors occur upstream of a coronagraph, they results…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Garima Singh , Frantz Martinache , Pierre Baudoz , Olivier Guyon , Taro Matsuo , Nemanja Jovanovic , Christophe Clergeon

Experimental characterization of magnetic components has grown to be increasingly important to understand and model their behaviours in high-frequency PWM converters. The BH loop measurement is the only available approach to separate the…

Signal Processing · Electrical Eng. & Systems 2025-10-08 Yakun Wang , Song Liu , Jun Wang , Binyu Cui , Jingrong Yang

Wavefront sensing and reconstruction are widely used for adaptive optics, aberration correction, and high-resolution optical phase imaging. Traditionally, interference and/or microlens arrays are used to convert the optical phase into…

We report an extensive numerical study and supporting experimental results on the spectral characterization of optical aberrations in macroscopic fluidic lenses with tunable focal distance and aperture shape. Using a Shack-Hartmann…

Optics · Physics 2023-12-19 Graciana Puentes , Fernando Minotti

The pyramid wavefront sensor (P-WFS) has replaced the Shack-Hartmann (SH-) WFS as sensor of choice for high performance adaptive optics (AO) systems in astronomy because of its flexibility in pupil sampling, its dynamic range, and its…

We present numerical characterizations of the wavefront sensing performance for few-mode photonic lantern wavefront sensors (PLWFSs). These characterizations include calculations of throughput, control space, sensor linearity, and an…

Instrumentation and Methods for Astrophysics · Physics 2023-11-06 Jonathan Lin , Michael P. Fitzgerald , Yinzi Xin , Yoo Jung Kim , Olivier Guyon , Sergio Leon-Saval , Barnaby Norris , Nemanja Jovanovic

The Hartmann test is a method used to measure the wavefront error in a focal optical system, wherein a mask with a pattern of small holes is placed at the system's aperture stop. By taking an image at a defocused plane, the differences…

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