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Related papers: Fast & Furious focal-plane wavefront sensing

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An ultrafast single-pixel optical 2D imaging system using a single multimode fiber (MF) is proposed. The MF acted as the all-optical random pattern generator. Light with different wavelengths pass through a single MF will generator…

Speckle Noise is the dominant source of error in high contrast imaging with adaptive optics system. We discuss the potential for wavefront sensing telemetry to calibrate speckle noise with sufficient precision and accuracy so that it can be…

Direct detection of exoplanets requires high dynamic range imaging. Coronagraphs could be the solution, but their performance in space is limited by wavefront errors (manufacturing errors on optics, temperature variations, etc.), which…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 Raphael Galicher , Pierre Baudoz , Gerard Rousset , Julien Totems , Marion Mas

It has previously been demonstrated in both simulation and experiment that well aligned remote focusing microscopes exhibit residual spherical aberration outside the focal plane. In this work, compensation of the residual spherical…

Optics · Physics 2023-05-17 Sharika Mohanan , Alexander D. Corbett

Strong turbulence conditions create amplitude aberrations through the effects of near-field diffraction. When integrated over long optical path lengths, amplitude aberrations (seen as scintillation) can nullify local areas in the recorded…

Instrumentation and Methods for Astrophysics · Physics 2020-12-30 Justin R. Crepp , Stanimir O. Letchev , Sam J. Potier , Joshua H. Follansbee , Nicholas T. Tusay

After releasing reference camera solutions in the visible and infrared for natural guide star wavefront sensing with unbeaten performance, we will present the first results of First Light Imaging s C-MORE, the first laser guide star…

Instrumentation and Methods for Astrophysics · Physics 2019-10-02 J. L. Gach , D. Boutolleau , A. Caillat , P. Feautrier , R. Pourcelot , E. Stadler

Recent work on Neural Radiance Fields (NeRF) showed how neural networks can be used to encode complex 3D environments that can be rendered photorealistically from novel viewpoints. Rendering these images is very computationally demanding…

Computer Vision and Pattern Recognition · Computer Science 2021-04-16 Stephan J. Garbin , Marek Kowalski , Matthew Johnson , Jamie Shotton , Julien Valentin

An adaptive optics system with a single deformable mirror is being implemented on the THEMIS 90cm solar telescope. This system is designed to operate in the visible and is required to be as robust as possible in order to deliver the best…

Instrumentation and Methods for Astrophysics · Physics 2021-01-11 Michel Tallon , Éric Thiébaut , Maud Langlois , Bernard Gelly , Richard Douet , Clémentine Béchet , Loïc Denis , Gil Moretto

The purpose of this work is to demonstrate a robust and clinically validated method for correcting sound speed aberrations in medical ultrasound. We propose a correction method that calculates focusing delays directly from the observed…

In this paper, we address the inverse problem of fast, stable, and high-quality wavefront reconstruction from pyramid wavefront sensor data for Adaptive Optics systems on Extremely Large Telescopes. For solving the indicated problem we…

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

In the classical bilateral filter, a fixed Gaussian range kernel is used along with a spatial kernel for edge-preserving smoothing. We consider a generalization of this filter, the so-called adaptive bilateral filter, where the center and…

Computer Vision and Pattern Recognition · Computer Science 2018-11-07 Ruturaj G. Gavaskar , Kunal N. Chaudhury

The Forward-Forward (FF) algorithm presents a compelling, bio-inspired alternative to backpropagation. However, while efficient in training, it has a computationally prohibitive inference process that requires a separate forward pass for…

Machine Learning · Computer Science 2026-05-04 Shalini Sarode , Brian Moser , Joachim Folz , Federico Raue , Tobias Nauen , Stanislav Frolov , Andreas Dengel

The ill-posed problem of phase retrieval in optics, using one or more intensity measurements, has a multitude of applications using electromagnetic or matter waves. Many phase retrieval algorithms are computed on pixel arrays using discrete…

Image and Video Processing · Electrical Eng. & Systems 2022-09-21 J. A. Pollock , K. S. Morgan , L. C. P. Croton , M. K. Croughan , G. Ruben , N. Yagi , H. Sekiguchi , M. J. Kitchen

Adaptive optics (AO) is critical in astronomy, optical communications and remote sensing to deal with the rapid blurring caused by the Earth's turbulent atmosphere. But current AO systems are limited by their wavefront sensors, which need…

Instrumentation and Methods for Astrophysics · Physics 2020-10-23 Barnaby R. M. Norris , Jin Wei , Christopher H. Betters , Alison Wong , Sergio G. Leon-Saval

Robust estimation is essential in computer vision, robotics, and navigation, aiming to minimize the impact of outlier measurements for improved accuracy. We present a fast algorithm for Geman-McClure robust estimation, FracGM, leveraging…

Computer Vision and Pattern Recognition · Computer Science 2024-11-22 Bang-Shien Chen , Yu-Kai Lin , Jian-Yu Chen , Chih-Wei Huang , Jann-Long Chern , Ching-Cherng Sun

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

Wavefront estimation using in-focus image data is critical to many applications. This data is invariant to a sign flip with complex conjugation of the complex amplitude in the pupil, making for a non-unique solution. Information from an…

Instrumentation and Methods for Astrophysics · Physics 2016-07-08 Alexandra Greenbaum , Anand Sivaramakrishnan

Fourier ptychographic microscopy (FPM) is a powerful computational imaging modality that achieves high space-bandwidth product imaging for biomedical samples. However, its adoption is limited by slow data acquisition due to the need for…

Optics · Physics 2025-09-09 Shi Zhao , Haowen Zhou , Changhuei Yang

We present a practical apparatus for characterizing optical aberrations of large collimation mirrors and lenses, and give a detailed analysis of wavefront-detection errors. We utilize a scanning pentaprism technique for precise measurements…

Optics · Physics 2022-05-13 Youn Seok Lee , Kimia Mohammadi , Thomas Jennewein

Following the recent developement of Fourier ptychographic microscopy (FPM) in the visible range by Zheng et al. (2013), we propose an adaptation for hard x-rays. FPM employs ptychographic reconstruction to merge a series of low-resolution,…

Instrumentation and Detectors · Physics 2016-09-27 H. Simons , H. F. Poulsen , J. P. Guigay , C. Detlefs
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