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During the last years the transfer of frequency signals through optical fibers has shown ultra low instabilities in various configurations. The outstanding experimental results of such point-to-point connections is motivation to develop a…

Optics · Physics 2019-10-25 M. Rost , M. Fujieda , D. Piester

Wave effects are often neglected in microlensing studies; however, for coherent point-like sources, such as pulsars and fast radio bursts (FRBs), wave effects will become important in their gravitational lensing. In this paper, we describe…

High Energy Astrophysical Phenomena · Physics 2020-08-12 Dylan L. Jow , Simon Foreman , Ue-Li Pen , Wei Zhu

A lunar orbit interferometer array suffers from a number of systematics. Beyond systematics induced by the imaging algorithm itself and thermal noise considered in Paper I, phase errors due to instrumental inconsistency between receivers,…

Instrumentation and Methods for Astrophysics · Physics 2026-04-01 Meng Zhou , Furen Deng , Yidong Xu , Li Zhou , Xuelei Chen

The Naval Research Laboratory and the National Radio Astronomy Observatory completed implementation of a low frequency capability on the VLA at 73.8 MHz in 1998. This frequency band offers unprecedented sensitivity (~25 mJy/beam) and…

Using the quantum interference of photon pairs in N-stage nonlinear interferometers (NLI), the contour of joint spectral function can be modified into islands pattern. We perform two series of experiments. One is that all the nonlinear…

Quantum Physics · Physics 2020-10-15 Mingyi Ma , Liang Cui , Xiaoying Li

We have developed a new phase referencing technique for high frequency VLBI observations. In conventional phase referencing, one interleaves short scans on a nearby phase calibrator between the target source observations. In fast frequency…

Astrophysics · Physics 2009-11-10 E. Middelberg , A. L Roy , R. C. Walker , H. Falcke

In this letter, we investigate a generic model assessing the effect of in-phase/quadrature-phase imbalance (IQI) on an asymmetric dual hop radio frequency/free space optical (RF/FSO) two-way relay (TWR) system in the presence of multiple…

Information Theory · Computer Science 2020-11-10 Abhijeet Upadhya , Juhi Gupta , Vivek K. Dwivedi , Mohamed-Slim Alouini

Many of the compact extragalactic radio sources that are used as fiducial points to define the celestial reference frame are known to have proper motions detectable with long-term geodetic/astrometric Very Long Baseline Interferometry…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-16 A. Moór , S. Frey , S. B. Lambert , O. Titov , J. Bakos

Spectral interference, the frequency counterpart of the beating phenomenon in the time domain, can severely distort time-frequency representations (TFRs) in physical applications. We study this phenomenon for the short-time Fourier…

Classical Analysis and ODEs · Mathematics 2026-01-19 Shrikant Chand , James Nolen , Hau-Tieng Wu

We study a non-Hermitian two-level system with square-wave modulated dissipation and coupling. Based on the Floquet theory, we achieve an effective Hamiltonian from which the boundaries of the $\mathcal{PT}$ phase diagram are captured…

Quantum Physics · Physics 2020-08-18 Liwei Duan , Yan-Zhi Wang , Qing-Hu Chen

In a standard interferometry experiment, one measures the phase difference between two paths by recombining the two wave packets on a beam-splitter. However, it has been recently recognized that the phase can also be estimated via local…

Quantum Physics · Physics 2021-01-01 Sebastian Horvat , Philippe Allard Guerin , Luca Apadula , Flavio Del Santo

With the current revival of interest in astronomical intensity interferometry, it is interesting to revisit the associated theory, which was developed in the 1950s and 1960s. This paper argues that intensity interferometry can be understood…

Instrumentation and Methods for Astrophysics · Physics 2020-09-17 Prasenjit Saha

Context. The current algorithms used for the calibration and analysis of very long baseline interferometry (VLBI) networks that only use linear polarizers (as is the case of the VLBI Global Observing System, VGOS) do not properly account…

Instrumentation and Methods for Astrophysics · Physics 2024-06-19 V. Pérez-Díez , I. Martí-Vidal , E. Albentosa-Ruiz , J. González-García , F. Jaron , T. Savolainen , M. H. Xu , R. Bachiller

Hanbury-Brown and Twiss (HBT) effect is the foundation for stellar intensity interferometry. However, it is a phase insensitive two-photon interference effect. In this paper, we extend the HBT interferometer by mixing two phase-coherent…

Quantum Physics · Physics 2025-02-07 Xuan Tang , Yunxiao Zhang , Xueshi Guo , Liang Cui , Xiaoying Li , Z. Y. Ou

A tomographic method is described to quantify the three-dimensional power-spectrum of the ionospheric electron-density fluctuations based on radio-interferometric observations by a two-dimensional planar array. The method is valid to…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 L. V. E. Koopmans

One of the aims of next generation optical interferometric instrumentation is to be able to make use of information contained in the visibility phase to construct high dynamic range images. Radio and optical interferometry are at the two…

Various phase transitions in models for coupled charge-density waves are investigated by means of the $\epsilon$-expansion, mean-field theory, and Monte Carlo simulations. At zero temperature the effective action for the system with…

Strongly Correlated Electrons · Physics 2009-11-10 Minchul Lee , Eun-Ah Kim , Jong Soo Lim , M. Y. Choi

The time-frequency integrals and the two-dimensional stationary phase method are applied to study the electromagnetic waves radiated by moving modulated sources in dispersive media. We show that such unified approach leads to explicit…

Quantum Physics · Physics 2012-12-11 Gennadiy Burlak , Vladimir Rabinovich

Atmospheric turbulence and aero-optic effects cause phase aberrations in propagating light waves, thereby reducing effectiveness in transmitting and receiving coherent light from an aircraft. Existing optical sensors can measure the…

Signal Processing · Electrical Eng. & Systems 2026-02-12 Jeffrey W. Utley , Gregery T. Buzzard , Charles A. Bouman , Matthew R. Kemnetz

We numerically investigate the feasibility and limits of jointly estimating flow fields and unknown particle properties (e.g., position, size, and density) from Lagrangian particle tracking (LPT) data. LPT offers time-resolved, volumetric…

Fluid Dynamics · Physics 2026-05-26 Ke Zhou , Samuel J. Grauer