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A new technique for contrast separation in wide-field magneto-optical Kerr microscopy is introduced. Utilizing the light from eight light emitting diodes, guided to the microscope by glass fibers and being switched synchronously with the…

Instrumentation and Detectors · Physics 2017-08-02 Ivan Soldatov , Rudolf Schäfer

The surface figure of x-ray mirrors can be improved by differential deposition of thin films. To achieve the required corrections, WSi2 layers of variable thickness were deposited through beam-defining apertures of different openings. The…

Optics · Physics 2025-06-03 Ch. Morawe , S. Labouré , F. Perrin , A. Vivo , R. Barrett

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

Ptychography is an imaging technique which involves a sample being illuminated by a coherent, localized probe of illumination. When the probe interacts with the sample, the light is diffracted and a diffraction pattern is detected. Then the…

Numerical Analysis · Mathematics 2023-01-31 Mark Iwen , Michael Perlmutter , Mark Philip Roach

A novel method capable of delivering relative optical path length metrology with nanometer precision is demonstrated. Unlike conventional dual-wavelength metrology which employs heterodyne detection, the method developed in this work…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Yitping Kok , Michael J. Ireland , J. Gordon Robertson , Peter G. Tuthill , Benjamin A. Warrington , William J. Tango

We present a detailed discussion of the implementation strategies for a recently developed $w$-stacking $w$-projection hybrid algorithm used to reconstruct wide-field interferometric images. In particular, we discuss the methodology used to…

Instrumentation and Methods for Astrophysics · Physics 2020-10-14 L. Pratley , M. Johnston-Hollitt , J. D. McEwen

This paper presents a novel technique for camera calibration using a single view that incorporates a spherical mirror. Leveraging the distinct characteristics of the sphere's contour visible in the image and its reflections, we showcase the…

Computer Vision and Pattern Recognition · Computer Science 2025-03-18 Nissim Barzilay , Ofek Narinsky , Michael Werman

When taking images against strong light sources, the resulting images often contain heterogeneous flare artifacts. These artifacts can importantly affect image visual quality and downstream computer vision tasks. While collecting real data…

Image and Video Processing · Electrical Eng. & Systems 2023-09-01 Yuyan Zhou , Dong Liang , Songcan Chen , Sheng-Jun Huang , Shuo Yang , Chongyi Li

In this paper, we aim to reconstruct an n-dimensional real vector from m phaseless measurements corrupted by an additive noise. We extend the noiseless framework developed in [15], based on mirror descent (or Bregman gradient descent), to…

Optimization and Control · Mathematics 2024-06-21 Jean-Jacques Godeme , Jalal Fadili , Claude Amra , Myriam Zerrad

Wide-field radio interferometric telescopes such as the Square Kilometre Array now being designed are subject to a number of aberrations. One particularly pernicious aberration is that due to non-coplanar baselines whereby long baselines…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 T. J. Cornwell , M. A. Voronkov , B. Humphreys

Adaptive optical correction is an efficient technique to obtain high-resolution images of the retinal surface. A main limitation of adaptive optical correction, however, is the small size of the corrected image. For medical purposes it is…

Optics · Physics 2015-03-27 Aglae Kellerer

We describe a high-speed single-shot multi-frame interferometric imaging technique enabling multiple interferometric images with femtosecond exposure time over a 50 ns event window to be recorded following a single laser-induced excitation…

We present a method to capture both 3D shape and spatially varying reflectance with a multi-view photometric stereo (MVPS) technique that works for general isotropic materials. Our algorithm is suitable for perspective cameras and nearby…

Computer Vision and Pattern Recognition · Computer Science 2020-01-22 Min Li , Zhenglong Zhou , Zhe Wu , Boxin Shi , Changyu Diao , Ping Tan

Complex object wave recovery from single-shot interference pattern is an important practical problem in interferometry and digital holography. The most popular single-shot interferogram analysis method involves Fourier filtering of…

Image and Video Processing · Electrical Eng. & Systems 2019-06-28 Sunaina , Mansi Butola , Kedar Khare

Chopping observations with a tip-tilt secondary mirror have conventionally been used in ground-based mid-infrared observations. However, it is not practical for next generation large telescopes to have a large tip-tilt mirror that moves at…

Since 2007, close binary and multiple stars are observed by speckle interferometry at the 4.1 m Southern Astrophysical Research (SOAR) telescope. The HRCam instrument, observing strategy and planning, data processing and calibration…

Instrumentation and Methods for Astrophysics · Physics 2018-02-21 Andrei Tokovinin

Off-axis parabolic mirrors (OAPs) are occasionally desirable for specialized applications, but are known to introduce field-dependent astigmatic aberrations. In an experiment where optical tweezers are formed by OAPs, another OAP is added…

Optics · Physics 2025-11-20 Meimei Liu , Yuqi Zhu , Giorgio Gratta

In this paper, we present a novel approach that can exactly recover extended targets in wave-based multistatic interferometric imaging, based on Generalized Wirtinger Flow (GWF) theory [1]. Interferometric imaging is a generalization of…

Signal Processing · Electrical Eng. & Systems 2020-11-10 Bariscan Yonel , Il-Young Son , Birsen Yazici

At present, the principal limitation on the resolution and contrast of astronomical imaging instruments comes from aberrations in the optical path, which may be imposed by the Earth's turbulent atmosphere or by variations in the alignment…

Instrumentation and Methods for Astrophysics · Physics 2015-10-23 Benjamin Pope , Peter Tuthill , Sasha Hinkley , Michael J. Ireland , Alexandra Greenbaum , Alexey Latyshev , John D. Monnier , Frantz Martinache

We introduce and experimentally implement Fourier-plane phase synchronization for optical microscopy, and demonstrate its performance with interferometric scattering microscopy. By combining a photothermal phase plate and laser beam…