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Related papers: Multiple spatial frequencies wavefront sensing

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A method for producing a laser guide star wavefront sensor for adaptive optics with reduced focal anisoplanatism is presented. A theoretical analysis and numerical simulations have been carried out and the results are presented. The…

Astrophysics · Physics 2009-11-11 T. Butterley , G. D. Love , R. W. Wilson , R. M. Myers , T. J. Morris

A perfectly collimated beam can be spread out by multiple scattering, creating a speckle pattern and increasing the etendue of the system. Standard optical systems conserve etendue, and thus are unable to reverse the process by transforming…

Optics · Physics 2021-07-23 Alba M. Paniagua-Diaz , William L. Barnes , Jacopo Bertolotti

Spatial sound field interpolation relies on suitable models to both conform to available measurements and predict the sound field in the domain of interest. A suitable model can be difficult to determine when the spatial domain of interest…

Audio and Speech Processing · Electrical Eng. & Systems 2022-11-30 Manuel Hahmann , Efren Fernandez-Grande

Wavefront sensors have now become core components in the fields of metrology of optical systems, biomedical optics, and adaptive optics systems for astronomy. However, none of the designs used or proposed so far achieve simultaneously a…

Optics · Physics 2024-07-04 F. Henault , Y. Feng , J. -J. Correia , L. Schreiber , A. Spang

Speech separation has been very successful with deep learning techniques. Substantial effort has been reported based on approaches over spectrogram, which is well known as the standard time-and-frequency cross-domain representation for…

Sound · Computer Science 2019-04-17 Gene-Ping Yang , Chao-I Tuan , Hung-Yi Lee , Lin-shan Lee

Multi-object or integral field spectrographs are recognized techniques for achieving simultaneous spectroscopic observations of different or extended sky objects with a high multiplex factor. In this communication is described a…

Instrumentation and Detectors · Physics 2016-12-14 Francois Henault , Florence Laurent

We introduce wavefront shaping as a tool for optimizing the sensitivity in nano-optomechanical measurement schemes. We perform multimode output analysis of an optomechanical system consisting of a focused laser beam coupled to the…

A variant of the complex Ginzburg-Landau equation is used to investigate the frequency locking phenomena in spatially extended systems. With appropriate parameter values, a variety of frequency-locked patterns including flats, $\pi$ fronts,…

Pattern Formation and Solitons · Physics 2009-11-07 Hwa-Kyun Park

Modern MIMO communication systems are almost exclusively designed under the assumption of locally plane wavefronts over antenna arrays. This is known as the far-field approximation and is soundly justified at sub-6-GHz frequencies at most…

Information Theory · Computer Science 2023-02-28 Giacomo Bacci , Luca Sanguinetti , Emil Björnson

This paper presents the basic principle and theoretical relationships of an original method allowing to retrieve the Wavefront Errors (WFE) of a ground or space-borne telescope when combining its main pupil with a second, decentered…

Optics · Physics 2011-05-19 Francois Henault

In this paper, we study the optimal spatio-temporal waveform design for active sensing applications. For this purpose a multi-antenna radar is exploited. The targets in the radar vision are naturally composed of multiple layers of different…

Information Theory · Computer Science 2019-03-01 Ali Kariminezhad , Aydin Sezgin

Spatial sampling is traditionally studied in a static setting where static sensors scattered around space take measurements of the spatial field at their locations. In this paper we study the emerging paradigm of sampling and reconstructing…

Multimedia · Computer Science 2015-06-12 Jayakrishnan Unnikrishnan , Martin Vetterli

Spatial, amplitude and phase variations in spatial functional data are confounded. Conclusions from the popular functional trace variogram, which quantifies spatial variation, can be misleading when analysing misaligned functional data with…

Methodology · Statistics 2020-10-20 Xiaohan Guo , Sebastian Kurtek , Karthik Bharath

We present a technique for measuring the transverse spatial properties of an optical wavefront. Intensity and phase profiles are recovered by analysis of a series of interference patterns produced by the combination of a scanning X-shaped…

Optics · Physics 2015-06-15 David T. Lloyd , Kevin O'Keeffe , Simon M. Hooker

Split-pulse x-ray photon correlation spectroscopy has been proposed as one of the unique capabilities made possible with the x-ray free electron lasers. It enables characterization of atomic scale structural dynamics that dictates the…

Instrumentation and Detectors · Physics 2020-05-06 Yanwen Sun , Mike Dunne , Paul Fuoss , Taito Osaka , Aymeric Robert , Mark Sutton , Makina Yabashi , Diling Zhu

Spatial channel covariance information can replace full knowledge of the entire channel matrix for designing analog precoders in hybrid multiple-input-multiple-output (MIMO) architecture. Spatial channel covariance estimation, however, is…

Information Theory · Computer Science 2017-11-15 Sungwoo Park , Robert W. Heath

The basic outline of a pupil plane WaveFront Sensor is reviewed taking into account that the source to be sensed could be different from an unresolved source, i.e. it is extended, and that it could deploy also in a 3D fashion, enough to…

In typical adaptive optics applications, the atmospheric residual turbulence affects the wavefront sensor response decreasing its sensitivity. On the other hand, wavefront sensors are generally calibrated in diffraction limited condition,…

Instrumentation and Methods for Astrophysics · Physics 2023-10-10 Guido Agapito , Carmelo Arcidiacono , Simone Esposito

It is known that a spatially partially coherent light field produces better imaging contrast compared to a spatially coherent field and that the contrast increases as the spatial coherence length of the field becomes smaller. The transverse…

Wavefront shaping allows focusing light through or inside strongly scattering media, but the background intensity also increases due to long-range correlations, reducing the target's contrast. By manipulating non-local intensity…