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Fluorescence Correlation Spectroscopy (FCS) yields measurement parameters (number of molecules, diffusion time) that characterize the concentration and kinetics of fluorescent molecules within a supposedly known observation volume. Absolute…

Biological Physics · Physics 2011-12-23 Charles Edouard Leroux , Irène Wang , Jacques Derouard , Antoine Delon

Even though the technology of adaptive optics (AO) is rapidly maturing, calibration of the resulting images remains a major challenge. The AO point-spread function (PSF) changes quickly both in time and position on the sky. In a typical…

To effectively apply passive speckle reduction methods, it is essential to use an illumination system that maximally exploits the non-ideal temporal coherence and angular diversity (spatial coherence reduction) of laser light. This study…

Optics · Physics 2025-04-28 A. Lapchuk , O. Prygun , D. Manko , I. Gorbov , Y. Morozov

Over the past fifty years, wavefront sensing technology has continuously evolved from basic techniques to high-precision systems, serving as a core methodology in adaptive optics (AO). Beyond traditional wavefront retrieval methods based on…

Optics · Physics 2025-05-13 Rundong Fan , Zichao Wang , Pei Li , Lei Huang

Optical imaging through scattering media is a fundamental challenge in many applications. Recently, substantial breakthroughs such as imaging through biological tissues and looking around corners have been obtained by the use of…

Optics · Physics 2020-07-09 Tomer Yeminy , Ori Katz

The next generation of adaptive optics (AO) systems will require tomographic reconstruction techniques to map the optical refractive index fluctuations, generated by the atmospheric turbulence, along the line of sight to the astronomical…

Instrumentation and Methods for Astrophysics · Physics 2014-01-07 H. W. Shepherd , J. Osborn , R. W. Wilson , T. Butterley , R. Avila , V. S. Dhillon , T. J. Morris

The WHT is unusually well-placed for exploitation of adaptive-optics (AO) technology. The site seeing is excellent (median 0.7 arcsec), dome seeing is negligible, and preliminary studies indicate that most of the atmospheric seeing…

Astrophysics · Physics 2009-11-06 C. R. Benn

Refraction by the atmosphere causes the positions of sources to depend on the airmass through which an observation was taken. This shift is dependent on the underlying spectral energy of the source and the filter or bandpass through which…

Instrumentation and Methods for Astrophysics · Physics 2019-05-01 Matthias Lee , Tamas Budavari , Ian Sullivan , Andrew Connolly

Upcoming large-scale spectroscopic surveys such as WEAVE and 4MOST will provide thousands of spectra of massive stars, which need to be analysed in an efficient and homogeneous way. Studies on massive stars are usually based on samples of a…

Solar and Stellar Astrophysics · Physics 2024-11-20 Joachim M. Bestenlehner

Extreme adaptive optics systems are now in operation across the globe. These systems, capable of high order wavefront correction, deliver Strehl ratios of 90% in the near-infrared. Originally intended for the direct imaging of exoplanets,…

Instrumentation and Methods for Astrophysics · Physics 2016-11-09 Nemanja Jovanovic , Christian Schwab , Nick Cvetojevic , Olivier Guyon , Frantz Martinache

Since the pioneering work of Arthur Ashkin, optical tweezers have become an indispensable tool for contactless manipulation of micro- and nanoparticles. Nowadays optical tweezers are employed in a myriad of applications demonstrating the…

We describe the results from a new instrument which combines Lucky Imaging and Adaptive Optics to give the first routine direct diffraction-limited imaging in the visible on a 5m telescope. With fast image selection behind the Palomar AO…

Adaptive optics can be used to mitigate the effects of atmospheric turbulence on imaging systems, but the correction is only partial, and deconvolution is often required to improve the resolution. This results in entire optical/digital…

Instrumentation and Methods for Astrophysics · Physics 2026-02-09 Florian Cheyssial , Laurent Mugnier , Cyril Petit

Adaptive (or deformable) mirrors are widely used as wavefront correctors in adaptive optics systems. The optical calibration of an adaptive mirror is a fundamental step during its life-cycle: the process is in facts required to compute a…

Instrumentation and Methods for Astrophysics · Physics 2022-10-11 Runa Briguglio , Marco Xompero , Armando Riccardi

Inhomogeneities in the refractive index of a biological sample can introduce phase aberrationsin microscopy systems, severely impairing the quality of images. Adaptive optics can be employed to correct for phase aberrations and improve…

Having a need to perform differential photometry for tens of thousands stars in a several square degrees field, we developed Astrokit program. The software corrects the star brightness variations caused by variations of atmospheric…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Artem Y. Burdanov , Vadim V. Krushinsky , Alexander A. Popov

We present a novel platform of optical tweezers which combines rapid prototyping of user-definable microlens arrays with spatial light modulation (SLM) for dynamical control of each associated tweezer spot. Applying femtosecond direct laser…

Diffusion Transformers (DiTs) achieve state-of-the-art results in text-to-image, text-to-video generation, and editing. However, their large model size and the quadratic cost of spatial-temporal attention over multiple denoising steps make…

Machine Learning · Computer Science 2025-09-24 Muhammad Adnan , Nithesh Kurella , Akhil Arunkumar , Prashant J. Nair

Adaptive Optics has become a key technology for the largest ground-based telescopes currently under or close to begin of construction. Adaptive optics is an indispensable component and has basically only one task, that is to operate the…

Instrumentation and Methods for Astrophysics · Physics 2019-01-24 Stefan Hippler

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
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