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Image segmentation plays a crucial role in extracting objects of interest and identifying their boundaries within an image. However, accurate segmentation becomes challenging when dealing with occlusions, obscurities, or noise in corrupted…

Computer Vision and Pattern Recognition · Computer Science 2025-08-12 Daoping Zhang , Xue-Cheng Tai , Lok Ming Lui

We propose a complete framework for the detection, astrometry, and photometry of faint companions from a sequence of adaptive optics corrected short exposures. The algorithms exploit the difference in statistics between the on-axis and…

Astrophysics · Physics 2011-02-11 Szymon Gladysz , Julian C. Christou

Directly imaging Earth-like exoplanets (``exoEarths'') with a coronagraph instrument on a space telescope requires a stable wavefront with optical path differences limited to tens of picometers RMS during exposure times of a few hours.…

This work introduces the first closed-loop adaptive optics (AO) system capable of optically correcting aberrations in real-time without a guidestar or a wavefront sensor. Nearly 40 years ago, Cederquist et al. demonstrated that asymmetric…

Image and Video Processing · Electrical Eng. & Systems 2026-05-14 Weiyun Jiang , Haiyun Guo , Christopher A. Metzler , Ashok Veeraraghavan

We present a method that enables wide field ground-based telescopes to scan the sky for sub-second stellar variability. The method has operational and image processing components. The operational component is to take star trail images. Each…

Instrumentation and Methods for Astrophysics · Physics 2018-11-28 David Thomas , Steven M Kahn

Plasmonic lasers (spasers) generate coherent surface-plasmon-polaritons (SPPs) and could be realized at subwavelength dimensions in metallic cavities for applications in nanoscale optics. Plasmonic cavities are also utilized for terahertz…

Optics · Physics 2016-07-26 Chongzhao Wu , Sudeep Khanal , John L. Reno , Sushil Kumar

In this work, we propose using camera arrays coupled with coherent illumination as an effective method of improving spatial resolution in long distance images by a factor of ten and beyond. Recent advances in ptychography have demonstrated…

Computer Vision and Pattern Recognition · Computer Science 2015-11-29 Jason Holloway , M. Salman Asif , Manoj Kumar Sharma , Nathan Matsuda , Roarke Horstmeyer , Oliver Cossairt , Ashok Veeraraghavan

Strong lensing time delay cosmography has excellent complementarity with other dark energy probes, and will soon have abundant systems detected. We investigate two issues in the imaging and spectroscopic followup required to obtain the time…

Cosmology and Nongalactic Astrophysics · Physics 2015-04-16 Eric V. Linder

Nonlinear frequency conversion in optics can originate the coherent light at the wavelength where it is hard or unlikely to achieve by directly lasing and is a fundamental topic in science and engineering covering both classical and quantum…

Optics · Physics 2019-12-02 Mingchuan Shao , Fei Liang , Haohai Yu , Huaijin Zhang

Optical stellar interferometers have demonstrated milli-arcsecond resolution with few apertures spaced hundreds of meters apart. To obtain rich direct images, many apertures will be needed, for a better sampling of the incoming wavefront.…

Instrumentation and Methods for Astrophysics · Physics 2014-09-17 Arun Surya , Swapan K. Saha , Antoine Labeyrie

We overview the current status of photometric analyses of images collected with Multi Conjugate Adaptive Optics (MCAO) at 8-10m class telescopes that operated, or are operating, on sky. Particular attention will be payed to resolved stellar…

The development of adaptive optics (AO) played a major role in modern astronomy over the last three decades. By compensating for the atmospheric turbulence, these systems enable to reach the diffraction limit on large telescopes. In this…

Instrumentation and Methods for Astrophysics · Physics 2017-01-05 Julien Milli , Dimitri Mawet , David Mouillet , Markus Kasper , Julien H. Girard

Contemporary approaches to optical multiple micro-manipulation typically involve careful pre-engineering of the laser beam shape. In various biomedical and microfluidic scenarios, especially those necessitating unconventional specimen…

Optics · Physics 2024-07-11 Ramin Jamali , Sabareesh K. P. Velu , Ali-Reza Moradi

The Global-Multi Conjugated Adaptive Optics (GMCAO) approach offers an alternative way to correct an adequate scientific Field of View (FoV) using only natural guide stars (NGSs) to extremely large ground-based telescopes. Thus, even in the…

Instrumentation and Methods for Astrophysics · Physics 2020-07-01 Elisa Portaluri , Valentina Viotto , Roberto Ragazzoni , Carmelo Arcidiacono , Maria Bergomi , Marco Dima , Davide Greggio , Jacopo Farinato , Demetrio Magrin

We propose a new strategy for obtaining enhanced resolution (FWHM = 0.12 arcsec) deep optical images over a wide field of view. As is well known, this type of image quality can be obtained in principle simply by fast guiding on a small (D =…

Astrophysics · Physics 2009-10-31 N. Kaiser , J. L. Tonry , G. A. Luppino

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

Cross-correlation of consecutive Doppler images is one of the most common techniques used to detect surface differential rotation (hereafter DR) on spotted stars. The disadvantage of a single cross-correlation is, however, that the expected…

Solar and Stellar Astrophysics · Physics 2015-06-17 Zsolt Kővári , János Bartus , Levente Kriskovics , Krisztián Vida , Katalin Oláh

Fabrication of optical coherence tomography (OCT) fiber probes in cardiology involves sequentially splicing and cleaving multiple fibers to form a lens. During this process, the splice location-normally invisible under standard…

We present the experimental realization of a laser system for ground to satellite optical Doppler ranging at the atmospheric turbulence limit. Such a system needs to display good frequency stability (a few parts in 10^{-14}) whilst allowing…

Optics · Physics 2013-11-12 Nicola Chiodo , Khelifa Djerroud , Ouali Acef , Andre Clairon , Peter Wolf

Meta-optics have rapidly become a major research field within the optics and photonics community, strongly driven by the seemingly limitless opportunities made possible by controlling optical wavefronts through interaction with arrays of…

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