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Related papers: Speckle Imaging with VLT/NACO No-AO Mode

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The World Space Observatory - Ultraviolet (WSO-UV) space telescope is equipped with high dispersion (55,000) spectrographs working in the 1150-3100 {\AA} spectral range. To evaluate the impact of the design on the scientific objectives of…

Instrumentation and Methods for Astrophysics · Physics 2017-06-13 Pablo Marcos-Arenal , Ana I. Gómez de Castro , Belén Perea Abarca , Mikhail Sachkov

An acousto-optic cell was used to reduce the speckle noise that reduces the quality of Hartmann-Shack and other wave-front sensors measuring ocular aberrations. In the method presented here, a laser beam traverses an acousto-optic cell,…

Optics · Physics 2007-05-23 V. Albanis , E. N. Ribak , Y. Carmon

SPHERE is the high-contrast exoplanet imager and spectrograph installed at the Unit Telescope 3 of the Very Large Telescope. After more than two years of regular operations, we analyse statistically the performance of the adaptive optics…

Instrumentation and Methods for Astrophysics · Physics 2018-07-03 J. Milli , D. Mouillet , T. Fusco , J. H. Girard , E. Masciadri , E. Pena , J. -F. Sauvage , C. Reyes , K. Dohlen , J. -L. Beuzit , M. Kasper , M. Sarazin , F. Cantalloube

Multi-object astronomical adaptive-optics (MOAO) is now a mature wide-field observation mode to enlarge the adaptive-optics-corrected field in a few specific locations over tens of arc-minutes. The work-scope provided by open-loop…

Instrumentation and Methods for Astrophysics · Physics 2023-07-19 Carlos M. Correia , Kate Jackson , Jean-Pierre Veran , David Andersen , Olivier Lardiere , Colin Bradley

Adaptive optics (AO) is a powerful image correction technique with proven benefits for many life-science microscopy methods. However, the complexity of adding a reflective wavefront modulator and a wavefront sensor into already complicated…

Ground-based ultra-high contrast imaging, as required for direct imaging of exoplanets and other solar systems, is limited by difficulty of separating the planetary emission from the effects of optical aberrations that are not compensated…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Richard A. Frazin

We study the efficiency of adaptive optics (AO) correction for the free-space propagation of entangled photonic orbital-angular-momentum (OAM) qubit states, to reverse moderate atmospheric turbulence distortions. We show that AO can…

In this paper, we present an original observational approach, which combines, for the first time, traditional speckle imaging with image post-processing to obtain in the optical domain diffraction-limited images with high contrast (1e-5)…

Acousto-optic tomography (AOT) enables optical-contrast imaging deep inside scattering samples via localized ultrasound modulation of scattered light. However, the resolution of AOT is inherently limited by the ultrasound focus size,…

Optics · Physics 2018-12-12 Daniel Doktofsky , Moriya Rosenfeld , Ori Katz

RISTRETTO is a visible high-resolution spectrograph fed by an extreme adaptive optics (AO) system, to be proposed as a visitor instrument on ESO VLT. The main science goal of RISTRETTO is to pioneer the detection and atmospheric…

A robust model for simulating speckle pattern evolution in optical coherence tomography (OCT) depending on the OCT system parameters and tissue deformation is reported. The model is based on application of close to reality procedures used…

Medical Physics · Physics 2014-11-04 V. Yu. Zaitsev , L. A. Matveev , A. L. Matveyev , G. V. Gelikonov , V. M. Gelikonov

Radio telescopes with off-axis feeds, such as the (E)VLA, suffer from "beam squint" in which the two orthogonal circular polarizations sampled have different pointing centers on the sky. Its effects are weak near the beam center but become…

Astrophysics · Physics 2008-07-02 Juan M. Uson , W. D. Cotton

Recently introduced angular-memory-effect based techniques enable non-invasive imaging of objects hidden behind thin scattering layers. However, both the speckle-correlation and the bispectrum analysis are based on the statistical average…

Optics · Physics 2017-11-22 Tengfei Wu , Jonathan Dong , Xiaopeng Shao , Sylvain Gigan

The Multi-adaptive optics Imaging CamerA for Deep Observations (MICADO) will image a field of view of nearly 1 arcminute at the diffraction limit of the Extremely Large Telescope (ELT), making use of the adaptive optics correction provided…

Hyperspectral imaging is useful for applications ranging from medical diagnostics to agricultural crop monitoring; however, traditional scanning hyperspectral imagers are prohibitively slow and expensive for widespread adoption. Snapshot…

Image and Video Processing · Electrical Eng. & Systems 2020-09-30 Kristina Monakhova , Kyrollos Yanny , Neerja Aggarwal , Laura Waller

Over the last few years, several interesting observations were obtained with the help of solar Adaptive Optics (AO). In this paper, few observations made using the solar AO are enlightened and briefly discussed. A list of disadvantages with…

Astrophysics · Physics 2009-11-13 K. Sankarasubramanian , T. Rimmele

Modern adaptive optics (AO) systems for large telescopes require tomographic techniques to reconstruct the phase aberrations induced by the turbulent atmosphere along a line of sight to a target which is angularly separated from the guide…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 James Osborn , Francisco Javier De Cos Juez , Dani Guzman , Timothy Butterley , Richard Myers , Andres Guesalaga , Jesus Laine

We introduce the RISTRETTO instrument for ESO VLT, an evolution from the original idea of connecting the SPHERE high-contrast facility to the ESPRESSO spectrograph (Lovis et al 2017). RISTRETTO is an independent, AO-fed spectrograph…

Capturing more information, e.g. geometry and material, using optical cameras can greatly help the perception and understanding of complex scenes. This paper proposes a novel method to capture the spectral and light field information…

Image and Video Processing · Electrical Eng. & Systems 2018-02-27 Qian Huang , Yunqian Li , Linsen Chen , Xiaoming Zhong , Jinli Suo , Zhan Ma , Tao Yue , Xun Cao

Speckle is the spatial fluctuation of irradiance seen when coherent light is reflected from a rough surface. It is due to light reflected from the surface's many nooks and crannies accumulating vastly-discrepant time delays, spanning much…

Optics · Physics 2020-08-26 Justin Dove , Jeffrey H. Shapiro