English
Related papers

Related papers: Focal-plane wavefront sensing with photonic lanter…

200 papers

Adaptive optics (AO) systems have significantly improved astronomical imaging capabilities over the last decade, and are revolutionizing the kinds of science possible with 4-5m class ground-based telescopes. A thorough understanding of AO…

Wavefront shaping is a technique for directing light through turbid media. The theoretical aspects of wavefront shaping are well understood, and under near-ideal experimental conditions, accurate predictions for the expected signal…

Optics · Physics 2024-07-01 Bahareh Mastiani , Daniël W. S. Cox , Ivo M. Vellekoop

The term wavefront sensor refers to the entire class of devices capable of measuring the optical wavefront of the incoming beam. Although numerous solutions have been proposed so far, recent advances in structured light have opened new…

Being accurate, efficient, and compact is essential to a facial landmark detector for practical use. To simultaneously consider the three concerns, this paper investigates a neat model with promising detection accuracy under wild…

Computer Vision and Pattern Recognition · Computer Science 2019-03-05 Xiaojie Guo , Siyuan Li , Jinke Yu , Jiawan Zhang , Jiayi Ma , Lin Ma , Wei Liu , Haibin Ling

The concept of pyramid wavefront sensors (PWFS) has been around about a decade by now. However, there is still a great lack of characterizing measurements that allow the best operation of such a system under real life conditions at an…

Astrophysics · Physics 2009-11-13 D. Peter , M. Feldt , B. Dorner , T. Henning , S. Hippler , J. Aceituno

In astronomy and microscopy, distortions in the wavefront affect the dynamic range of a high contrast imaging system. These aberrations are either imposed by a turbulent medium such as the atmosphere, by static or thermal aberrations in the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-18 Benjamin Pope , Nick Cvetojevic , Anthony Cheetham , Frantz Martinache , Barnaby Norris , Peter Tuthill

In principle, diffractive optics, particularly Phase Fresnel Lenses (PFLs), offer the ability to construct large, diffraction-limited, and highly efficient X-ray/$\gamma$-ray telescopes, leading to dramatic improvement in angular resolution…

In astronomy or biological imaging, refractive index inhomogeneities of e.g. atmosphere or tissues induce optical aberrations which degrade the desired information hidden behind the medium. A standard approach consists in measuring these…

Optics · Physics 2023-06-01 Tengfei Wu , Marc Guillon , Gilles Tessier , Pascal Berto

The ingot WFS is a new kind of wavefront sensor specifically designed to deal with the elongation of LGS reference sources on ELT-class telescopes. Like the pyramid, it belongs to the family of pupil plane wavefront sensors and can be…

Lensless imaging enables exceptionally compact fluorescence sensors, advancing applications in \textit{in vivo} imaging and low-cost, point-of-care diagnostics. These sensors require a filter to block the excitation light while passing…

Image and Video Processing · Electrical Eng. & Systems 2026-02-20 Lukas Harris , Micah Roschelle , Jack Bartley , Mekhail Anwar

Photonic lanterns are an important enabling technology for astrophotonics with a wide range of potential applications including fibre Bragg grating OH suppression, integrated photonic spectrographs and fibre scramblers for high resolution…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Anthony Horton , Robert Content , Simon Ellis , Jon Lawrence

With the Extremely Large Telescope-generation telescopes come new challenges. The complexity of these telescopes' pupil creates new problems for Adaptive Optics. In particular, the large spiders necessary to support the massive optics of…

Photonic lantern nulling (PLN) is a method for enabling the detection and characterization of close-in exoplanets by exploiting the symmetries of the ports of a mode-selective photonic lantern (MSPL) to cancel out starlight. A six-port MSPL…

Context. With the arrival of the next generation of ground-based imaging interferometers combining from 4 to possibly 6 telescopes simultaneously, there is also a strong need for a new generation of fringe trackers able to cophase such…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 N. Blind , O. Absil , J. -B. Lebouquin , J. -P. Berger , A. Chelli

We present two complementary algorithms suitable for using focal-plane measurements to control a wavefront corrector with an extremely high spatial resolution. The algorithms use linear approximations to iteratively minimize the aberrations…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 Visa Korkiakoski , Christoph U. Keller , Niek Doelman , Matthew Kenworthy , Gilles Otten , Michel Verhaegen

The subwavelength mode volumes of plasmonic filters are well matched to the small size of state-of-the-art active pixels (~ 1 {\mu}m) in CMOS image sensor arrays used in portable electronic devices. Typical plasmonic filters exhibit broad…

Optics · Physics 2017-11-22 Dagny Fleischman , Luke Sweatlock , Hirotaka Murakami , Harry Atwater

Wavefront sensing in solar adaptive-optics is currently done with correlating Shack-Hartmann sensors, although the spatial- and temporal-resolutions of the phase measurements are then limited by the extremely fast computing required to…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Aglae Kellerer

Ground-based direct imaging of exoplanets at high contrast requires precise correction of atmospheric turbulence using adaptive optics (AO). The planet-to-star contrast ratio at small angular separations from the host star is often limited…

The classic Hartmann test consists of an array of holes to reconstruct the wavefront from the local deviation of each focal spot, and Shack-Hartmann sensor improved that with an array of microlenses. This array of microlenses imposes…

Optics · Physics 2019-12-02 Job Mendoza-Hernandez , Dorilian Lopez-Mago

The pressing need for the detailed wavefront properties of ultra-bright and ultra-short pulses produced by free-electron lasers (FELs) has spurred the development of several complementary characterization approaches. Here we present a…