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The advent of graphene and related 2D materials has recently led to a new technology: heterostructures based on these atomically thin crystals. The paradigm proved itself extremely versatile and led to rapid demonstration of tunnelling…

In absence of a lens to form an image, incoherent or partially coherent light scattering off an obstructive or reflective object forms a broad intensity distribution in the far field with only feeble spatial features. We show here that…

We propose the construction of a prototype scanner designed to capture multispectral images of documents. A standard sheet-feed scanner is modified by disconnecting its internal light source and connecting an external multispectral light…

Computer Vision and Pattern Recognition · Computer Science 2019-04-30 Zohaib Khan , Faisal Shafait , Ajmal Mian

Harvesting condensed atmospheric vapour as dew water can be an alternative or complementary potable water resource in specific arid or insular areas. Such radiation-cooled condensing devices use already existing flat surfaces (roofs) or…

Fluid Dynamics · Physics 2007-07-18 O. Clus , Jalil Ouazzani , M. Muselli , Vadim Nikolayev , Girja Sharan , D. Beysens

Low-light-level imaging techniques have application in many diverse fields, ranging from biological sciences to security. We demonstrate a single-photon imaging system based on a time-gated inten- sified CCD (ICCD) camera in which the image…

We have constructed a large format mosaic CCD camera for the Sloan Digital Sky Survey. The camera consists of two arrays, a photometric array which uses 30 2048 x 2048 SITe/Tektronix CCDs (24 micron pixels) with an effective imaging area of…

Astrophysics · Physics 2011-05-23 J. Gunn , M. Carr , C. Rockosi , M. Sekiguchi

Salient object detection (SOD) is a long-standing research topic in computer vision and has drawn an increasing amount of research interest in the past decade. This paper provides the first comprehensive review and benchmark for light field…

Computer Vision and Pattern Recognition · Computer Science 2022-07-12 Keren Fu , Yao Jiang , Ge-Peng Ji , Tao Zhou , Qijun Zhao , Deng-Ping Fan

A light source of selective functionalities of wavelengths, illumination periods, and intensities is desirable for investigating performance parameters as well as the quality of different layers and interfaces of solar cells. Conventional…

Instrumentation and Detectors · Physics 2023-02-16 Md. Saidul Islam , Syed Farid Uddin Farhad , Md. Saidul Islam , Nazmul Islam Tanvir , Suravi Islam

Currently, no light source exists which is both narrow-band and speckle-free with sufficient brightness for full-field imaging applications. Light emitting diodes (LEDs) are excellent spatially incoherent sources, but are tens of nanometers…

In 2016, an exposure meter was installed on the Lijiang Fiber-fed High-Resolution Spectrograph to monitor the coupling of starlight to the science fiber during observations. Based on it, we investigated a method to estimate the exposure…

Instrumentation and Methods for Astrophysics · Physics 2024-02-06 Xiao-Guang Yu , Kai-Fan Ji , Xi-Liang Zhang , Liang Chang , Yun-Fang Cai , Ying Qin , Zhen-Hong Shang

The tilt, rotation, or offset of each CCD with respect to the focal plane, as well as the distortion of the focal plane itself, cause shape distortions to the observed objects, an effect typically known as field distortion (FD). We point…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-24 Jun Zhang , Fuyu Dong , Hekun Li , Xiangchong Li , Yingke Li , Dezi Liu , Wentao Luo , Liping Fu , Guoliang Li , Zuhui Fan

X-ray emission spectroscopy is a well-established technique used to study continuum lowering in dense plasmas. It relies on accurate atomic physics models to robustly reproduce high-resolution emission spectra, and depends on our ability to…

Plasma Physics · Physics 2020-01-22 M. F. Kasim , J. S. Wark , S. M. Vinko

A new application of a fast CCD drift scanning technique that allows us to perform speckle imaging of binary stars is presented. For each observation, an arbitrary number of speckle frames is periodically stored on a computer disk, each…

Astrophysics · Physics 2007-05-23 O. Fors , E. P. Horch , J. Nunez

Image coaddition is one of the most basic operations that astronomers perform. In Paper~I, we presented the optimal ways to coadd images in order to detect faint sources and to perfrom flux measurements under the assumption that the noise…

Instrumentation and Methods for Astrophysics · Physics 2018-03-28 Barak Zackay , Eran O. Ofek

Optical lattice loaded with cold atoms can exhibit a tunable photonic band gap for a weak probe field under the conditions of electromagnetically induced transparency. This system possesses a number of advantageous properties, including…

Quantum Physics · Physics 2011-11-10 David Petrosyan

Detecting parity violation on cosmological scales would provide a striking clue to new physics. Large-scale structure offers the raw statistical power -- many three-dimensional modes -- to make such tests. However, for scalar observables,…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-09 Zucheng Gao , Azadeh Moradinezhad Dizgah , Zvonimir Vlah

We have developed a new method to correct dark current at relatively high temperatures for Charge-Coupled Device (CCD) images when dark frames cannot be obtained on the telescope. For images taken with the Antarctic Survey Telescopes (AST3)…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Bin Ma , Zhaohui Shang , Yi Hu , Qiang Liu , Lifan Wang , Peng Wei

We report on the investigation of an approach for modelling light transmission through systems consisting of several jointed optical fibres, in which the analytical modelling of the waveguides was replaced by Finite Element Modelling (FEM)…

Applied Physics · Physics 2018-07-31 Natascia Castagna , Jacques Morel , Luc Testa , Sven Burger

Photonic crystal fibres (PCFs) are optical fibres that guide light using a modulated dielectric medium. They provide an exceptionally versatile platform for various applications, thanks to the flexibility with which light-guiding can be…

We present a system of X-ray photometry for the Chandra satellite. X-ray photometry can be a powerful tool to obtain flux estimates, hardness ratios, and colors unbiased by assumptions about spectral shape and independent of temporal and…

Astrophysics · Physics 2008-12-18 H. -J. Grimm , J. McDowell , G. Fabbiano , M. Elvis