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Programmable integrated photonics has evolved into a potent platform for implementing diverse optical functions on a single chip through software-driven reconfiguration. At the core of these processors are the photonic waveguide meshes that…

Optics · Physics 2025-10-21 Jacek Gosciniak

Wireless backhaul communication has been recently realized with large antennas operating in the millimeter wave (mmWave) frequency band and implementing highly directional beamforming. In this paper, we focus on the alignment problem of…

Information Theory · Computer Science 2017-10-13 George C. Alexandropoulos

Antenna arrays will be an important ingredient in millimeter wave (mmWave) cellular systems. A natural application of antenna arrays is simultaneous transmission to multiple users. Unfortunately, the hardware constraints in mmWave systems…

Information Theory · Computer Science 2016-11-18 Ahmed Alkhateeb , Geert Leus , Robert W. Heath

An efficient technique to produce a periodic sequence of ultrashort pulses of recoilless gamma-radiation via its transmission through the optically thick vibrating resonant absorber was demonstrated recently [Nature, 508, 80 (2014)]. In…

We describe a method for producing high power, coherent x-ray pulses from a free electron laser with femtosecond scale periodic temporal modulation of the polarization vector. This approach relies on the generation of a temporal intensity…

Accelerator Physics · Physics 2020-12-30 Nicholas Sudar , Ryan Coffee , Erik Hemsing

A method to temporally tailor the properties of X-ray radiation carrying Orbital Angular Momentum (OAM) is presented. In simulations, an electron beam is prepared with a temporally modulated micro-bunching structure which, when radiating at…

Accelerator Physics · Physics 2022-05-04 J. Morgan , B. W. J. McNeil

A fast-wave pulse in a simple, cold, inhomogeneous MHD model plasma is constructed by Fourier superposition over frequency of harmonic waves that are singular at their respective Alfven resonances. The pulse partially reflects before…

Solar and Stellar Astrophysics · Physics 2010-11-17 C S Hanson , P S Cally

Characterizing resonant scatterers is challenging because their poles and zeros usually lie away from the real-frequency axis, whereas most measurements sample only real frequencies and infer off-axis behavior from fitted models. Here we…

Optics · Physics 2026-03-16 Alex Krasnok , Denis Seletskiy

We propose a time-delayed model for the study of active mode-locking that is valid for large values of the round-trip gain and losses. It allows us to access the typical regimes encountered in semiconductor lasers and to perform an extended…

Optics · Physics 2024-10-08 Elias R. Koch , Svetlana V. Gurevich , Julien Javaloyes

A high-power laser pulse at normal incidence onto a plane solid target will generate odd harmonics of its frequency. However, the spacing of the harmonic lines in this configuration is fixed. Here, we study harmonic generation using two…

Optics · Physics 2025-01-20 Raoul Trines , Holger Schmitz , Martin King , Paul McKenna , Robert Bingham

Transmission through photoexcited semiconductors is used to temporally and spectrally shape a Terahertz pulse. By adjusting the optical pump-THz probe delay, we experimentally introduce a polar asymmetry in the pulse profile as high as 92%.…

In molecular communication (MC), combining different types of particles at the transmitter is a degree of freedom which can be utilized to improve performance. In this paper, we address the problem of pulse shaping to simplify time…

Emerging Technologies · Computer Science 2023-03-15 Wayan Wicke , Rebecca C. Felsheim , Lukas Brand , Vahid Jamali , Helene M. Loos , Andrea Buettner , Robert Schober

We present three classes of symmetric broadband composite pulse sequences. The composite phases are given by analytic formulas (rational fractions of $\pi$) valid for any number of constituent pulses. The transition probability is expressed…

Quantum Physics · Physics 2018-04-18 Boyan T. Torosov , Nikolay V. Vitanov

We report a systematic investigation into the processes behind a near hundredfold enhanced second harmonic wave generated from a laser-induced air plasma, by examining the temporal dynamics of the frequency conversion processes, and the…

Pulsar timing now has a rich history in placing limits on the stochastic background of gravitational waves, and we plan soon to reach the sensitivity where we can detect, not just place limits on, the stochastic background. However, the…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Andrea N. Lommen

Elastic metamaterials made from locally resonant arrays have been developed as effective ways to create band gaps for elastic or acoustic travelling waves. They work by implementing stationary states in the structure that localise and…

Classical Physics · Physics 2023-03-09 Luca Iorio , Jacopo M. De Ponti , Alberto Corigliano , Raffaele Ardito

Comparative analysis of second harmonic generation in ordinary and backward-wave settings is presented. Extraordinary properties of frequency doubling nonlinear optical reflectivity and pulse shaping through phase matching of ordinary and…

Optics · Physics 2016-02-02 Alexander K. Popov , Sergey A. Myslivets

The temporal shape of a pulse in transcranial magnetic stimulation (TMS) influences which neuron populations are activated preferentially as well as the strength and even direction of neuromodulation effects. Furthermore, various pulse…

Medical Physics · Physics 2022-02-15 Z. Li , J. Zhang , A. V. Peterchev , S. M. Goetz

The modular design of planar phased arrays arranged on orthogonal polygon-shaped apertures is addressed and a new method is proposed to synthesize domino-tiled arrays fitting multiple, generally conflicting, requirements. Starting from an…

Applied Physics · Physics 2022-05-18 Paolo Rocca , Nicola Anselmi , Alessandro Polo , Andrea Massa

We propose a general one-dimensional {\em continuous} formulation to analyze the vibrational modes of antenna-like nanomechanical resonators consisting of two symmetric arrays of cantilevers affixed to a central nano-beam. The cantilever…

Mathematical Physics · Physics 2015-05-13 J. Dorignac , A. Gaidarzhy , P. Mohanty