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The discovery of the exoplanet Proxima b highlights the potential for the coming generation of giant segmented mirror telescopes (GSMTs) to characterize terrestrial --- potentially habitable --- planets orbiting nearby stars with direct…

Instrumentation and Methods for Astrophysics · Physics 2017-12-21 Jared R. Males , Olivier Guyon

The air entrainment due to the turbulence in a free surface boundary layer shear flow created by a horizontally moving vertical surface-piercing wall is studied through experiments and direct numerical simulations. In the experiments, a…

The upcoming extremely large telescopes will have to deal with the so-called ''pupil fragmentation'' effect: for what concerns the Extremely Large Telescope (ELT), the presence of thick spider legs supporting the secondary mirror may induce…

Instrumentation and Methods for Astrophysics · Physics 2024-06-05 G. Carlà , L. Busoni , S. Esposito , G. Agapito , R. Holzlöhner

We present a spatio-temporal mechanism for producing 2D optical rogue waves in the presence of a turbulent state with creation, interaction and annihilation of optical vortices. Spatially periodic structures with bound phase lose stability…

Optics · Physics 2016-02-12 Christopher J. Gibson , Alison M. Yao , Gian-Luca Oppo

While Fourier ptychography (FP) offers super-resolution for macroscopic imaging, its real-world application is severely hampered by atmospheric turbulence, a challenge largely unaddressed in existing macroscopic FP research operating under…

Stratified flows forced by internal waves similar to those obtained in the Coriolis platform (LEGI, Grenoble, France) \cite{Savaro2020} are studied by pseudospectral triply-periodic simulations. The experimental forcing mechanism consisting…

SPHERE, operating at the VLT since 2014, is currently one of the high-contrast instruments with a higher performance. Its adaptive optics system, known as SAXO, will be upgraded to SAXO+, which features the addition of a second stage of…

Atmospheric turbulence significantly degrades long-range imaging by introducing geometric warping and exposure-time-dependent blur, which adversely affects both visual quality and the performance of high-level vision tasks. Existing methods…

Computer Vision and Pattern Recognition · Computer Science 2026-03-04 Junwei Zeng , Dong Liang , Sheng-Jun Huang , Kun Zhan , Songcan Chen

Plasmonic metasurfaces are able to modify the wavefront by altering the light intensity, phase and polarization state. Active plasmonic metasurfaces would allow dynamic modulation of the wavefront which give rise to interesting application…

In the last decade, progresses in additive manufacturing (AM) have paved the way for optimized heat exchangers, whose disruptive design will depend on predictive numerical simulations. Typical AM rough surfaces show limited resemblance to…

Fluid Dynamics · Physics 2023-05-10 Himani Garg , Lei Wang , Guillaume Sahut , Christer Fureby

Atmospheric profiling is a requirement for controlling wide-field Adaptive Optics (AO) instruments, analyzing the AO performance with respect to the observing conditions and predicting the Point Spread Function (PSF) spatial variations. We…

Instrumentation and Methods for Astrophysics · Physics 2019-04-17 Olivier Beltramo-Martin , Nazim A. Bharmal , Carlos M. Correia

This paper describes the data preprocessing and reduction methods together with SLODAR analysis and wind profiling techniques for GeMS: the Gemini MCAO System. The wavefront gradient measurements of the five GeMS's Shack-Hartmann sensors,…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Angela Cortés , Benoit Neichel , Andrés Guesalaga , James Osborn , Francois Rigaut , Dani Guzman

An Adaptive Spiral Phase Plate (ASPP) based on liquid crystal (LC) and the transmission electrode technique is theoretically and experimentally demonstrated. This ASPP design enables the generation of high-quality optical vortices with…

Atmospheric turbulence causes fluctuations in the local refractive index of air that accumulatively disturb a wave's phase and amplitude distribution as it propagates. This impairs the effective range of laser weapons as well as the…

Optics · Physics 2015-06-02 Chensheng Wu , Jonathan Ko , Christopher C. Davis

The conversion of phase variations in an optical wavefield into intensity information is of fundamental importance for optical imaging technology including microscopy of biological cells. While conventional approaches to phase-imaging…

Optics · Physics 2022-09-07 Lukas Wesemann , Jon Rickett , Timothy J. Davis , Ann Roberts

The investigation of metasurface, which is of great current interest, has opened up new degrees of freedom to research metamaterials. In this paper, we propose an ultrathin acoustic metasurface consisting of a series of structurally simple…

Classical Physics · Physics 2016-06-03 Shilong Zhai , Changlin Ding , Huaijun Chen , Song Liu , Chunrong Luo , Xiaopeng Zhao

The internal antarctic plateau revealed in the last years to be a site with interesting potentialities for the astronomical applications due to the extreme dryness and low temperatures, the typical high altitude of the plateau, the weak…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 E. Masciadri , F. Lascaux , S. Hagelin , P. Le Moigne , J. Noilhan

Theoretically and experimentally we have proved the existence of optimal thickness of the porous layer used as an anti-reflection coating in solar cells. We have taken into account the joint mechanisms of generation and recombination of…

Mesoscale and Nanoscale Physics · Physics 2017-02-17 Zeinulla Zhanabaev , Kadyrzhan Dikhanbayev

A new scenario for the interaction of a jet with a background medium with cold clouds is investigated by means of hydrodynamic turbulence simulations with cooling. The idea is that the cold clouds are overtaken by a radio cocoon and stirred…

Astrophysics · Physics 2008-11-26 Martin Krause

Recently, new artificial material has been proposed to control an electromagnetic wave-metasurface, a two-dimensional metamaterial. Compared with a three-dimensional bulky metamaterial, this artificial plane material with sub-wavelength…

Optics · Physics 2019-07-12 Chong Sheng , Hui Liu , Shining Zhu