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This paper describes a comprehensive measurement model for the error budget of pulse arrival times with emphasis on intrinsic pulse jitterand plasma propagation effects (particularly interstellar scattering), which are stochastic in time…

Instrumentation and Methods for Astrophysics · Physics 2010-10-20 J. M. Cordes , R. M. Shannon

The recent discovery of ultra-long wavelength gravitational waves through the advent of pulsar timing arrays (PTA) has opened up new avenues for fundamental science. Here we show that every PTA source will be diffractively lensed by…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-04 Dylan L. Jow , Ue-Li Pen

Electrical pulse stimulation drives many important physical phenomena in condensed matter as well as in electronic systems and devices. Often, nanoscopic and mesoscopic mechanisms are hypothesized, but methods to image electrically driven…

Mesoscale and Nanoscale Physics · Physics 2023-06-05 Thomas E Gage , Daniel B Durham , Haihua Liu , Supratik Guha , Ilke Arslan , Charudatta Phatak

Diffuse optical tomography (DOT) use near-infrared light for imaging optical properties of biological tissues. Time-domain DOT systems use pulsed lasers and measure time-varying temporal point spread function (TPSF), carrying information…

Optics · Physics 2023-01-10 Meghdoot Mozumder , Jarkko Leskinen , Tanja Tarvainen

The filamentational instability of spatially broadband femtosecond optical pulses in air is investigated by means of a kinetic wave equation for spatially incoherent photons. An explicit expression for the spatial amplification rate is…

Optics · Physics 2009-11-11 M. Marklund , P. K. Shukla

Pulsar timing experiments require high fidelity template profiles in order to minimize the biases in pulse time-of-arrival (TOA) measurements and their uncertainties. Efforts to acquire more precise TOAs given fixed effective area of…

High Energy Astrophysical Phenomena · Physics 2019-01-30 Timothy T. Pennucci

Radio telescopes are used to accurately measure the time of arrival (ToA) of radio pulses in pulsar timing experiments that target mostly millisecond pulsars (MSPs) due to their high rotational stability. This allows for detailed study of…

Instrumentation and Methods for Astrophysics · Physics 2015-09-09 Griffin Foster , Aris Karastergiou , Remi Paulin , Tobia Carozzi , Simon Johnston , Willem van Straten

Precise measurement of multi-parameters of ultrafast lasers is vital both in scientific investigations and technical applications, such as, optical field manipulation, pulse shaping, sample characteristics test, and biomedical imaging.…

The recent introduction of coherent optical communications has created a compelling need for ultra-fast phase-sensitive measurement techniques operating at milliwatt peak power levels and in time scales ranging from sub-picoseconds to…

The space-time focusing of a (continuous) succession of localized X-shaped pulses is obtained by suitably integrating over their speed, i.e., over their axicon angle, thus generalizing a previous (discrete) approach. First, new Superluminal…

Classical Physics · Physics 2009-11-10 M. Zamboni Rached , Amr Shaarawi , Erasmo Recami

Conventional techniques that measure rapid time variations are inefficient or inadequate to discover and observe rapidly pulsating astronomical sources. It is therefore conceivable that there exist some classes of objects pulsating with…

Instrumentation and Methods for Astrophysics · Physics 2015-05-18 Ermanno F Borra

It is critical to characterize the carrier and instantaneous frequency distribution variation in ultrafast processes, all of which are determined by the optical phase. Nevertheless, there is no method that can single-shot record the…

Optics · Physics 2021-06-18 Wenchao Wang , Tianhao Xian , Li Zhan

A real-time ranging lidar with 0.1 Mega Hertz update rate and few-micrometer resolution incorporating dispersive Fourier transformation and instantaneous microwave frequency measurement is proposed and demonstrated. As time-stretched…

Signal Processing · Electrical Eng. & Systems 2020-08-06 Lijie Zhao , Haiyun Xia , Yihua Hu , Tengfei Wu , Zhen Zhang , Jibo Han , Yunbin Wu , Tiancheng Luo

Due to their broad spectral width, ultrashort lasers provide new possibilities to shape light beams and control their properties, in particular through the use of spatio-temporal couplings. In this context, we present a theoretical…

Optics · Physics 2017-08-22 Antonin Sainte-Marie , Olivier Gobert , Fabien Quere

Here we present a Bayesian method of including discrete measurements of dispersion measure due to the interstellar medium in the direction of a pulsar as prior information in the analysis of that pulsar. We use a simple simulation to show…

Instrumentation and Methods for Astrophysics · Physics 2013-12-10 Lindley Lentati , Paul Alexander , Michael P. Hobson

Traditionally devoted to electron density profile measurement we show that fast frequency sweeping reflectometry technique can bring valuable and innovative measurements onto plasma turbulence. While fast frequency sweeping technique is…

Plasma Physics · Physics 2007-05-23 F. Clairet , L. Vermare , S. Heuraux , G. Leclert

This paper presents a temporal paraxial formulation for the propagation of ultrashort optical pulses in time-modulated media with slowly varying refractive index. By deriving the paraxial wave equation directly in the time domain from the…

Optics · Physics 2026-01-29 Antonio Alex-Amor , Carlos Molero

With a collecting area of 70 000 m^2, the Five hundred metre Aperture Spherical Telescope (FAST) will allow for great advances in pulsar astronomy. We have performed simulations to estimate the number of previously unknown pulsars FAST will…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 R. Smits , D. R. Lorimer , M. Kramer , R. Manchester , B. Stappers , C. J. Jin , R. D. Nan , D. Li

The concept of super-resolution refers to various methods for improving the angular resolution of an optical imaging system beyond the classical diffraction limit. Although several techniques to narrow the central lobe of the illumination…

Instrumentation and Methods for Astrophysics · Physics 2017-04-11 Luca Olmi , Pietro Bolli , Luca Cresci , Francesco D'Agostino , Massimo Migliozzi , Daniela Mugnai , Enzo Natale , Renzo Nesti , Dario Panella , Lorenzo Stefani

Streaking of photoelectrons with optical lasers has been widely used for temporal characterization of attosecond extreme ultraviolet pulses. Recently, this technique has been adapted to characterize femtosecond x-ray pulses in free-electron…