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We present time-resolved X-ray diffraction measurements using advanced timing schemes that provide high temporal resolution while also maintaining a high flux in the X-ray probe beam. The method employs patterned probe pulse sequences that…

Irradiating intercalated nanorings by optical vortices ignites a charge flow that emits coherent trains of high harmonic bursts with frequencies and time structures that are controllable by the topological charge of the driving vortex beam.…

量子物理 · 物理学 2017-11-22 J. Wätzel , J. Berakdar

A pulse of matter waves may dramatically change its shape when traversing an absorbing barrier with time-dependent transparency. Here we show that this effect can be utilized for controlled manipulation of spatially-localized quantum…

量子物理 · 物理学 2015-05-04 Arseni Goussev

We generate high-order harmonics in gaseous medium with tunable photon energy using time domain interferometry of double pulses in a non-collinear generation geometry. The method is based on the fact that the generated harmonics inherit…

Purpose: To investigate dipole antennas with electronically switchable transmit field patterns to improve flip angle homogeneity in ultra-high field MRI Methods: An array of eight coaxial dipoles with electronically switchable $B_{1}^{\!+}$…

This paper proposes an asymptotically optimal hybrid beamforming solution for large antenna arrays by exploiting the properties of the singular vectors of the channel matrix. It is shown that the elements of the channel matrix with Rayleigh…

信息论 · 计算机科学 2016-08-10 Sohail Payami , Mir Ghoraishi , Mehrdad Dianati

Beamforming is a signal processing technique where an array of antenna elements can be steered to transmit and receive radio signals in a specific direction. The usage of millimeter wave (mmWave) frequencies and multiple input multiple…

One of the uses of sensor arrays is for spatial filtering or beamforming. Current digital signal processing methods facilitate complex-weighted beamforming, providing flexibility in array design. Previous studies proposed the use of…

音频与语音处理 · 电气工程与系统科学 2024-01-05 V. Tourbabin , M. Agmon , B. Rafaely , J. Tabrikian

We study plasmonic time crystals, an extension of dielectric-based photonic time crystals to plasmonic media. Remarkably, we demonstrate that such systems may amplify both longitudinal and transverse modes. In particular, we show that…

Noninvasive brain stimulation can write signals into neurons but requires power electronics with exceptionally high power in the mega-volt-ampere range and kilohertz usable bandwidth. Whereas oscillator circuits offered only one or very few…

系统与控制 · 电气工程与系统科学 2025-09-03 Jinshui Zhang , Stefan M. Goetz

A possibility to greatly enhance frequency-conversion efficiency of stimulated Raman scattering is shown by making use of extraordinary properties of three-wave mixing of ordinary and backward waves. Such processes are commonly attributed…

Recently, Chumak et al. have demonstrated experimentally the time-reversal of microwave spin pulses based on non-adiabatically tuning the wave speed in a spatially-periodic manner. Here, we solve the associated wave equations analytically,…

光学 · 物理学 2015-05-28 Yonatan Sivan , John B. Pendry

Coherent control over photoelectron wavepackets, via the use of polarization-shaped laser pulses, can be understood as a time and polarization-multiplexed process. In this work, we investigate this multiplexing via computation of the…

原子物理 · 物理学 2016-05-30 Paul Hockett , Matthias Wollenhaupt , Thomas Baumert

The root raised-cosine pulse commonly used in linear digital modulations yields exactly two intersymbol interference components from the preceding and the subsequent data symbols, provided that the roll-off factor is $100\%$ and the…

信息论 · 计算机科学 2023-01-05 Pavel Loskot

Multimode fibers (MMFs) have recently reemerged as attractive avenues for nonlinear effects due to their high-dimensional spatiotemporal nonlinear dynamics and scalability for high power. High-brightness MMF sources with effective control…

光学 · 物理学 2023-12-07 Tong Qiu , Honghao Cao , Kunzan Liu , Li-Yu Yu , Manuel Levy , Eva Lendaro , Fan Wang , Sixian You

Controlling the temporal mode shape of quantum light pulses has wide ranging application to quantum information science and technology. Techniques have been developed to control the bandwidth, allow shifting in the time and frequency…

A new, programmed pulse width modulation (PWM) technique to control power inverters, which uses a harmonic injection modulator and a frequency modulated triangular carrier, synchronized with the modulating signal is presented in this paper.…

A new carrier-based pulse-width modulation (PWM) technique to control power inverters is presented in this paper. To generate the output waveform, this technique compares a harmonic-injection modulating wave and a frequency-modulated…

It is shown theoretically that the use of accelerating spatiotemporal quasi-phase-matching (QPM) modulation patterns in media with parametric optical interactions makes it possible to generate a time-reversed replica of the pump pulse…

光学 · 物理学 2016-10-17 Michal Yachini , Boris Malomed , Alon Bahabad

We present a novel photonic beamformer for a fully integrated transmit phased array antenna, together with an automatic procedure for tuning the delays in this system. Such an automatic tuning procedure is required because the large number…

应用物理 · 物理学 2019-07-12 L. Bliek , S. Wahls , I. Visscher , C. Taddei , R. B. Timens , R. Oldenbeuving , C. Roeloffzen , M. Verhaegen