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One of the major challenges of employing a dual-frequency phase-shifting algorithm for phase retrieval is its sensitivity to noise. Yun et. al [H Yun, B Li, S Zhang. 2017] proposed a dual-frequency method based on the Fourier transform…

Instrumentation and Detectors · Physics 2018-05-23 Minmin Wang , Canlin Zhou , Shuchun Si , Zhenkun Lei , Xiaolei Li , Hui Li , YanJie Li

Interferometric imaging is a well established method to image phase objects by mixing the image wavefront with a reference one on a CCD camera. It has also been applied to fast transient phenomena, mostly through the analysis of single…

Fourier ptychography (FP), as a computational imaging method, is a powerful tool to improve imaging resolution. Camera-scanning Fourier ptychography extends the application of FP from micro to macro creatively. Due to the non-ideal scanning…

Image and Video Processing · Electrical Eng. & Systems 2022-06-08 Baiqi Cui , Shaohui Zhang , Yechao Wang , Yao Hu , Qun Hao

Future Extremely Large Telescopes will adopt segmented primary mirrors with several hundreds of segments. Cophasing of the segments together is essential to reach high wavefront quality. The phasing sensor must be able to maintain very high…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Arthur Vigan , Kjetil Dohlen , Silvio Mazzanti

Phase-shifting electron holography is an excellent method to reveal electron wave phase information with very high phase sensitivity over a large range of spatial frequencies. It circumvents the limiting trade-off between fringe spacing and…

Materials Science · Physics 2024-04-19 J. Lindner , U. Ross , T. Meyer , V. Boureau , M. Seibt , Ch. Jooss

This paper investigates the problem of joint phase tracking and channel decoding in OFDM based Physical-layer Network Coding (PNC) systems. OFDM signaling can obviate the need for tight time synchronization among multiple simultaneous…

Information Theory · Computer Science 2013-12-30 Taotao Wang , Soung Chang Liew

In order to increase the measured phase of an atom interferometer and improve its sensitivity, researchers attempt to increase the enclosed space-time area using two methods: creating larger separations between the interferometer arms and…

Fourier ptychographic microscopy (FPM) is a recently developed imaging modality that uses angularly varying illumination to extend a system performance beyond the limit defined by its optical elements. The FPM technique applies a novel…

Optics · Physics 2014-05-02 Xiaoze Ou , Roarke Horstmeyer , Changhuei Yang , Guoan Zheng

We present a real-time differential phasefront detector sensitive to better than 3 mrad rms, which corresponds to a precision of about 500 pm. This detector performs a spatially resolving measurement of the phasefront of a heterodyne…

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

For sensitive optical interferometry, it is crucial to control the evolution of the optical path difference (OPD) of the wavefront between the individual telescopes of the array. The OPD between a pair of telescopes is induced by…

Instrumentation and Methods for Astrophysics · Physics 2021-12-28 Saavidra Perera , Jörg-Uwe Pott , Julien Woillez , Martin Kulas , Wolfgang Brandner , Sylvestre Lacour , Felix Widmann

To enable optical long baseline interferometry toward faint objects, long integrations are necessary despite atmospheric turbulence. Fringe trackers are needed to stabilize the fringes and thus increase the fringe visibility and phase…

Instrumentation and Methods for Astrophysics · Physics 2014-09-10 Élodie Choquet , Jonathan Menu , Guy Perrin , Frédéric Cassaing , Sylvestre Lacour , Frank Eisenhauer

This paper reviews two techniques that have been recently published for 3D profilometry and proposes one shot profilometry using iterative two-step temporal phase-unwrapping by combining the composite fringe projection and the iterative…

Instrumentation and Detectors · Physics 2016-05-24 Guangliang Du , Minmin Wang , Canlin Zhou , Shuchun Si , Hui Li , Zhenkun Lei , Yanjie Li

We describe a high-speed single-shot multi-frame interferometric imaging technique enabling multiple interferometric images with femtosecond exposure time over a 50 ns event window to be recorded following a single laser-induced excitation…

The technique of frequency phase transfer (FPT), enabled by multiband receivers with shared optical path (SOP), is set to become a true backbone of VLBI operations at frequencies above 22 GHz. The FPT has been successfully implemented at…

To achieve high data rates defined in 5G, the use of millimeter-waves and massive-MIMO are indispensable. To benefit from these technologies, an accurate estimation of the channel parameters is crucial. We propose a novel two-stage…

Signal Processing · Electrical Eng. & Systems 2020-07-15 Fazal-E-Asim , Felix Antreich , Charles C. Cavalcante , André L. F. de Almeida , Josef A. Nossek

Strong turbulence conditions create amplitude aberrations through the effects of near-field diffraction. When integrated over long optical path lengths, amplitude aberrations (seen as scintillation) can nullify local areas in the recorded…

Instrumentation and Methods for Astrophysics · Physics 2020-12-30 Justin R. Crepp , Stanimir O. Letchev , Sam J. Potier , Joshua H. Follansbee , Nicholas T. Tusay

Quantum interferometry uses quantum resources to improve phase estimation with respect to classical methods. Here we propose and theoretically investigate a new quantum interferometric scheme based on three-dimensional waveguide devices.…

Quantum Physics · Physics 2013-01-09 N. Spagnolo , L. Aparo , C. Vitelli , A. Crespi , R. Ramponi , R. Osellame , P. Mataloni , F. Sciarrino

Hyperspectral cameras have recently been miniaturized for operation on lightweight airborne platforms such as UAV or small aircraft. Unlike frame cameras (RGB or Multispectral), many hyperspectral sensors use a linear array or 'push-broom'…

Computer Vision and Pattern Recognition · Computer Science 2024-09-11 Julien Yuuki Burkhard , Jesse Ray Murray Lahaye , Laurent Valentin Jospin , Jan Skaloud

Being inspired by the biological eye, event camera is a novel asynchronous technology that pose a paradigm shift in acquisition of visual information. This paradigm enables event cameras to capture pixel-size fast motions much more…

Computer Vision and Pattern Recognition · Computer Science 2024-06-26 David El-Chai Ben-Ezra , Ron Arad , Ayelet Padowicz , Israel Tugendhaft
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