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Related papers: Point-Spread Function of the Optics in Scanning El…

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Images of electron flow through a two-dimensional electron gas from a quantum point contact (QPC) can be obtained at liquid He temperatures using scanning probe microscopy (SPM). A negatively charged SPM tip depletes the electron gas…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 B. J. LeRoy , A. C. Bleszynski , M. A. Topinka , R. M. Westervelt , S. E. J. Shaw , E. J. Heller , K. D. Maranowski , A. C. Gossard

The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to detect photons with energies from 20 MeV to > 300 GeV. The pre-launch response functions of the LAT were determined through…

High Energy Astrophysical Phenomena · Physics 2016-03-23 LAT Collaboration

We have developed a new technique for weak lensing analysis, with which the effect of the point spread function (PSF) on small galaxy images can be corrected for accurately. Rather than relying on weighted second moments of detected images,…

Astrophysics · Physics 2016-08-30 Konrad Kuijken

In this work, we propose a structured illumination (SI) method based on a two-photon excitation (TPE) scanning laser beam. Advantages of TPE methods include optical sectioning, low photo-toxicity, and robustness in the face of sample…

Biological Physics · Physics 2016-09-16 Alex Bardales , Qinggele Li , Bingzhao Zhu , Xiaodong Tao , Marc Reinig , Joel Kubby

Simulated images are essential in algorithm development and instrument testing for optical telescopes. During real observations, images obtained by optical telescopes are affected by spatially variable point spread functions (PSFs), a…

Instrumentation and Methods for Astrophysics · Physics 2025-02-17 Zeyu Bai , Peng Jia , Jiameng Lv , Xiang Zhang , Wennan Xiang , Lin Nie

Ground based optical telescopes are seriously affected by atmospheric turbulence induced aberrations. Understanding properties of these aberrations is important both for instruments design and image restoration methods development. Because…

Instrumentation and Methods for Astrophysics · Physics 2020-04-08 Peng Jia , Xuebo Wu , Yi Huang , Bojun Cai , Dongmei Cai

We propose a compact snapshot monocular depth estimation technique that relies on an engineered point spread function (PSF). Traditional approaches used in microscopic super-resolution imaging such as the Double-Helix PSF (DHPSF) are…

Image and Video Processing · Electrical Eng. & Systems 2022-08-05 Bhargav Ghanekar , Vishwanath Saragadam , Dushyant Mehra , Anna-Karin Gustavsson , Aswin Sankaranarayanan , Ashok Veeraraghavan

Context. Future weak lensing surveys, such as the Euclid mission, will attempt to measure the shapes of billions of galaxies in order to derive cosmological information. These surveys will attain very low levels of statistical error, and…

We investigate the ellipticity of the point-spread function (PSF) produced by imaging an unresolved source with a telescope, subject to the effects of atmospheric turbulence. It is important to quantify these effects in order to understand…

Astrophysics · Physics 2011-02-11 W. H. de Vries , S. S. Olivier , S. J. Asztalos , L. J. Rosenberg , K. L. Baker

The point-spread function (PSF) of an adaptive optics (AO) system is often poorly known. This ignorance can lead to significant systematic errors in photometry. Since the degree of AO correction is sensitive to the observing conditions:…

Astrophysics · Physics 2010-11-11 Christopher D. Sheehy , Nate McCrady , James R. Graham

Accessing the point-spread function (PSF) of a complex optical system is important for a variety of imaging applications. However, placing an invasive point source is often impractical, and estimating it blindly with multiple frames is slow…

Optics · Physics 2020-09-23 Tengfei Wu , Jonathan Dong , Sylvain Gigan

Point-spread function (PSF) estimation in spatially undersampled images is challenging because large pixels average fine-scale spatial information. This is problematic when fine-resolution details are necessary, as in optimal photometry…

Instrumentation and Methods for Astrophysics · Physics 2021-02-03 Teresa Symons , Michael Zemcov , James Bock , Yun-Ting Cheng , Brendan Crill , Christopher Hirata , Stephanie Venuto

Quantum gas microscopes, which image the atomic occupations in an optical lattice, have opened a new avenue to the exploration of many-body lattice systems. Imaging trapped systems after freezing the density distribution by ramping up a…

Quantum Gases · Physics 2019-05-10 Sven Krönke , Maxim Pyzh , Christof Weitenberg , Peter Schmelcher

Scanning Electron Microscopy (SEM) is a widely used tool for nanoparticle characterization, but long-term directional drift can compromise image quality. We present a novel algorithm for post-imaging drift correction in SEM nanoparticle…

The Point Spread Function (PSF) is a key figure of merit for specifying the angular resolution of optical systems and, as the demand for higher and higher angular resolution increases, the problem of surface finishing must be taken…

Instrumentation and Methods for Astrophysics · Physics 2016-10-04 K. Tayabaly , D. Spiga , G. Sironi , R. Canestrari , M. Lavagna , G. Pareschi

The shape of a focus-modulated point spread function (PSF) is used as a quick visual assessment tool of aberration modes in the PSF. Further analysis in terms of shape moments can permit quantifying the modal coefficients with an accuracy…

Instrumentation and Methods for Astrophysics · Physics 2014-08-11 Hanshin Lee

In a scanning transmission electron microscope (STEM), producing a high-resolution image generally requires an electron beam focused to the smallest point possible. However, the magnetic lenses used to focus the beam are unavoidably…

A new type of excitations by highly focused electron beams in scanning transmission electron microscopes is predicted for nanoparticles. The calculated electron energy loss spectra of metallic (silver) and insulating (SiO(sub2))…

Materials Science · Physics 2011-11-09 M. A. Itskovsky , H. Cohen , T. Maniv

We examined the anisotropic point spread function (PSF) of Suprime-Cam data utilizing dense star field data. We decomposed the PSF ellipticities into three components, the optical aberration, atmospheric turbulence, and chip-misalignment in…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Takashi Hamana , Satoshi Miyazaki , Yuki Okura , Tomohiro Okamura , Toshifumi Futamase

Nanoparticles (NPs) have proven their applicability in biosensing, drug delivery, and photo-thermal therapy, but their performance depends critically on the distribution and number of functional groups on their surface. When studying…