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An image-based technique for measuring the complex field in the pupil of an imaging system is presented. Two point source images, one with a small modification introduced in the pupil, are combined using a simple and non-iterative…

Optics · Physics 2013-09-27 Johanan L. Codona

In many signal processing problems arising in practical applications, we wish to reconstruct an unknown signal from its phaseless measurements with respect to a frame. This inverse problem is known as the phase retrieval problem. For each…

Information Theory · Computer Science 2023-07-04 Palina Salanevich

Wavefront shaping has revolutionized imaging deep in scattering media, being able to spatially and temporally refocus light through or inside the medium. However, wavefront shaping is not compatible yet with polarization-resolved microscopy…

Optics · Physics 2018-11-26 Hilton B. de Aguiar , Sylvain Gigan , Sophie Brasselet

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

For the first time, this paper investigates the phase retrieval problem with the assumption that the phase (of the complex signal) is sparse in contrast to the sparsity assumption on the signal itself as considered in the literature of…

Optimization and Control · Mathematics 2019-01-29 Hieu Thao Nguyen , D. Russell Luke , Oleg Soloviev , Michel Verhaegen

We present an alternative numerical reconstruction algorithm for direct tomographic reconstruction of a sample refractive indices from the measured intensities of its far-field coherent diffraction patterns. We formulate the well-known…

Computational Physics · Physics 2019-02-06 T. Ramos , Bastian E. Grønager , Martin Skovgaard Andersen , J. W. Andreasen

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

Point spread function (PSF) reconstruction (PSF-R) is a well established technique to determine reliably and accurately the PSF from Adaptive Optics (AO) control loop data. We have successfully applied this technique to improve the…

Instrumentation and Methods for Astrophysics · Physics 2020-04-15 Olivier Beltramo-Martin , Antonino Marasco , Thierry Fusco , Davide Massari , Julien Milli , Giuliana Fiorentino , B. Neichel

We propose and demonstrate a new phase retrieval method for imaging through random media. Although methods to recover the Fourier amplitude through random distortions are well established, recovery of the Fourier phase has been a more…

Optics · Physics 2021-05-14 Byungjae Hwang , Taeseong Woo , Cheolwoo Ahn , Jung-Hoon Park

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…

X-ray phase-contrast imaging has the potential to improve image contrast with lower dose by probing an object's refractive properties as well as its absorptive properties. To reconstruct a phase-contrast image from a raw dataset, a phase…

Medical Physics · Physics 2025-08-19 Giavanna Jadick , Patrick La Rivière

Knowledge of the electric field of femtosecond, high intensity laser pulses is of paramount importance to study the interaction of this class of lasers with matter. A novel, hybrid method to reconstruct the laser field from fluence…

Computational Physics · Physics 2023-09-19 Ioaquin Moulanier , Lewis Thomas Dickson , Francesco Massimo , Brigitte Cros

We consider a region $M$ in $\mathbb{R}^n$ with boundary $\partial M$ and a metric $g$ on $M$ conformal to the Euclidean metric. We analyze the inverse problem, originally formulated by Dix, of reconstructing $g$ from boundary measurements…

Analysis of PDEs · Mathematics 2012-12-04 Maarten V. de Hoop , Sean F. Holman , Einar Iversen , Matti Lassas , Bjørn Ursin

Optical imperfections, misalignments, aberrations, and even dust can significantly limit sensitivity in high-contrast imaging systems such as coronagraphs. An upstream deformable mirror (DM) in the pupil can be used to correct or compensate…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Johanan L. Codona , Matthew Kenworthy

We report a new coherent imaging technique, termed ptychographic structured modulation (PSM), for quantitative super-resolution microscopy. In this technique, we place a thin diffuser (i.e., a scattering lens) in between the sample and the…

Image and Video Processing · Electrical Eng. & Systems 2019-07-26 Pengming Song , Shaowei Jiang , He Zhang , Zichao Bian , Chengfei Guo , Kazunori Hoshino , Guoan Zheng

Shack-Hartmann wavefront sensors (SHWS) are generally used to measure the wavefront curvature of light beams. Measurement accuracy and the sensitivity of these sensors are important factors for better wavefront sensing. In this study, we…

Optics · Physics 2021-10-04 Nitin Dubey , Ravi Kumar , Joseph Rosen

This paper proposes a new framework to regularize the highly ill-posed and non-linear phase retrieval problem through deep generative priors using simple gradient descent algorithm. We experimentally show effectiveness of proposed algorithm…

Machine Learning · Computer Science 2018-08-20 Fahad Shamshad , Ali Ahmed

We present a new algorithm, FRiM (FRactal Iterative Method), aiming at the reconstruction of the optical wavefront from measurements provided by a wavefront sensor. As our application is adaptive optics on extremely large telescopes, our…

Mathematical Physics · Physics 2015-05-18 Eric Thiebaut , Michel Tallon

Poisson Surface Reconstruction is a widely-used algorithm for reconstructing a surface from an oriented point cloud. To facilitate applications where only partial surface information is available, or scanning is performed sequentially, a…

Graphics · Computer Science 2025-06-06 Sidhanth Holalkere , David S. Bindel , Silvia Sellán , Alexander Terenin

Extreme wavefront correction is required for coronagraphs on future space telescopes to reach 1e-8 or better starlight suppression for the direct imaging and characterization of exoplanets in reflected light. Thus, a suite of wavefront…

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