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Imaging below the diffraction limit is always a public interest because of the restricted resolution of conventional imaging systems. To beat the limit, evanescent harmonics decaying in space must participate in the imaging process. Here,…

Optics · Physics 2019-10-02 Tie-Jun Huang , Li-Zheng Yin , Ya Shuang , Jiang-Yu Liu , Yunhua Tan , Pu-Kun Liu

In long-baseline interferometry, bandwidth smearing of an extended source occurs at finite bandwidth when its different components produce interference packets that only partially overlap. In this case, traditional model fitting or image…

Instrumentation and Methods for Astrophysics · Physics 2013-08-07 Régis Lachaume , Jean-Philippe Berger

Intensity interferometry permits very long optical baselines and the observation of sub-milliarcsecond structures. Using planned kilometric arrays of air Cherenkov telescopes at short wavelengths, intensity interferometry may increase the…

Instrumentation and Methods for Astrophysics · Physics 2015-03-17 Dainis Dravins , Hannes Jensen , Stephan LeBohec , Paul D. Nuñez

We present RESOLVE, a new algorithm for radio aperture synthesis imaging of extended and diffuse emission in total intensity. The algorithm is derived using Bayesian statistical inference techniques, estimating the surface brightness in the…

Instrumentation and Methods for Astrophysics · Physics 2016-02-03 H. Junklewitz , M. R. Bell , M. Selig , T. A. Enßlin

Recording and identifying faint objects through atmospheric scattering media by an optical system are fundamentally interesting and technologically important. In this work, we introduce a comprehensive model that incorporates contributions…

Optics · Physics 2024-04-24 Libang Chen , Jun Yang , Lingye Chen , Yuyang Shui , Yikun Liu , Jianying Zhou

Multispectral mid-infrared (2-5 ${{\mu}m}$) imaging is a critical capability across science and technology, offering a window into the vibrational and thermal landscape of matter that is inaccessible to visible sensors. It bridges the…

Optics · Physics 2026-01-29 Daniel Beitner , Ziv Abelson , Eyal Hollander , Omri Meron , Haim Suchowski

We report on a new x-ray imaging method, which combines the high spatial resolution of coherent diffraction imaging with the ability of dark field microscopy to map grains within thick polycrystalline specimens. An x-ray objective serves to…

Instrumentation and Detectors · Physics 2020-07-15 Anders Filsøe Pedersen , Virginie Chamard , Carsten Detlefs , Tao Zhou , Dina Carbone , Henning Friis Poulsen

The APerture SYNthesis SIMulator is a simple interactive tool to help the students visualize and understand the basics of the Aperture Synthesis technique, applied to astronomical interferometers. The users can load many different…

Instrumentation and Methods for Astrophysics · Physics 2017-06-07 Ivan Marti-Vidal

A novel approach for measuring fast oscillations of an absolute value of interferometer optical path difference (OPD) has been developed. The principles of frequency-scanning interferometry are utilized for registration of the…

Instrumentation and Detectors · Physics 2019-05-01 Nikolai Ushakov , Leonid Liokumovich

Diverse applications in photonics and microwave engineering require a means of measurement of the instantaneous frequency of a signal. A photonic implementation typically applies an interferometer equipped with three or more output ports to…

Just as turbulence in the Earth's atmosphere can severely limit the angular resolution of optical telescopes, turbulence in the ionized interstellar medium fundamentally limits the resolution of radio telescopes. We present a scattering…

Instrumentation and Methods for Astrophysics · Physics 2016-12-14 Michael D. Johnson

We propose a high resolution spatial diagnostic method via inserting a millimeter-gap grating into the collimated terahertz beam to monitor the minute variation of the terahertz beam in strong-field terahertz sources, which is difficult to…

This paper introduces a new and novel radar interferometry based on Doppler synthetic aperture radar (Doppler-SAR) paradigm. Conventional SAR interferometry relies on wideband transmitted waveforms to obtain high range resolution.…

Computational Engineering, Finance, and Science · Computer Science 2018-04-18 Birsen Yazici , Il-Young Son , H. Cagri Yanik

Recent successes in image synthesis are powered by large-scale diffusion models. However, most methods are currently limited to either text- or image-conditioned generation for synthesizing an entire image, texture transfer or inserting…

Computer Vision and Pattern Recognition · Computer Science 2023-05-23 Yufei Ye , Xueting Li , Abhinav Gupta , Shalini De Mello , Stan Birchfield , Jiaming Song , Shubham Tulsiani , Sifei Liu

A novel and simple approach to optical wavelength measurement is presented in this paper. The working principle is demonstrated using a tunable waveguide micro ring resonator and single photodiode. The initial calibration is done with a set…

Interferometric imaging now achieves angular resolutions as fine as 10 microarcsec, probing scales that are inaccessible to single telescopes. Traditional synthesis imaging methods require calibrated visibilities; however, interferometric…

Instrumentation and Methods for Astrophysics · Physics 2018-04-25 Andrew A. Chael , Michael D. Johnson , Katherine L. Bouman , Lindy L. Blackburn , Kazunori Akiyama , Ramesh Narayan

The far-field resolution of optical imaging systems is restricted by the Abbe diffraction limit, a direct result of the wave nature of light. One successful technological approach to circumventing this limit is to reduce the effective size…

Optical imaging of the intensity, phase and polarization distributions of optical field is fundamental to numerous applications. Traditional methods rely on bulky optical components and require multiple measurements. Recently,…

Optics · Physics 2024-08-19 Yanjun Bao , Baojun Li

Hyperspectral imaging has become a significant source of valuable data for astronomers over the past decades. Current instrumental and observing time constraints allow direct acquisition of multispectral images, with high spatial but low…

Computer Vision and Pattern Recognition · Computer Science 2019-12-30 Claire Guilloteau , Thomas Oberlin , Olivier Berné , Nicolas Dobigeon

Radio astronomical observation below 30 MHz is hampered by the refraction and absorption of the ionosphere, and the radio frequency interference (RFI), so far high angular resolution sky intensity map is not available. An interferometer…

Instrumentation and Methods for Astrophysics · Physics 2018-07-09 Qizhi Huang , Shijie Sun , Shifan Zuo , Fengquan Wu , Yidong Xu , Bin Yue , Reza Ansari , Xuelei Chen
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