English
Related papers

Related papers: Tailoring spatiotemporal wavepackets via two-dimen…

200 papers

We report on the diffraction-free propagation of space-time wave packets (STWPs) -- a class of propagation-invariant pulsed beams -- for $\sim\!1$ km in an open-air laser range in a low-turbulence scenario. Making use of $\approx\!100$-fs…

Stimulated Emission Depletion (STED) microscopy has emerged as a powerful technique providing visualization of biological structures at the molecular level in living samples. In this technique, the diffraction limit is broken by selectively…

The investigation of spatio-temporal couplings (STCs) of broadband light beams is becoming a key topic for the optimization as well as applications of ultrashort laser systems. This calls for accurate measurements of STCs. Yet, it is only…

In this work, we design and investigate contrast-independent partially explicit time discretizations for wave equations in heterogeneous high-contrast media. We consider multiscale problems, where the spatial heterogeneities are at subgrid…

Numerical Analysis · Mathematics 2022-07-20 Eric T. Chung , Yalchin Efendiev , Wing Tat Leung , Petr N. Vabishchevich

Spatio-temporal shaping of electron beams is a bold frontier in electron microscopy, enabling new routes toward spatial-resolution enhancement, selective probing, low-dose imaging and faster data acquisition. Over the last decade, shaping…

Stacked intelligent metasurfaces (SIMs) represent a key enabler for next-generation wireless networks, offering beamforming gains while significantly reducing radio-frequency chain requirements. In conventional space-only SIM architectures,…

Signal Processing · Electrical Eng. & Systems 2026-04-29 Donatella Darsena , Ivan Iudice , Vincenzo Galdi , Francesco Verde

Time-varying media, characterized by dynamic or spacetime-modulated constitutive parameters such as permittivity and permeability, have recently emerged as a transformative paradigm for advanced wave control, transcending the constraints…

Optics · Physics 2026-04-20 Youxiu Yu , Hao Hu , Qianru Yang , Linyang Zou , Dongjue Liu , Hao Chi Zhang , Yu Luo

We demonstrate how a narrowband pump and a broadband spectrum can be spatially multiplexed by selective coupling them in two distinct modes of a few-mode microstructure fiber. The first mode carries most of the input pump energy, and…

The advent of spatiotemporal wave packets (STWPs), represented by spatiotemporal optical vortices (STOVs), has paved the way for the exploration in optics and photonics. To date, despite considerable efforts, a comprehensive and efficient…

This paper presents space-time varying (STV) metasurfaces for simultaneously controlling the spatial and temporal spectra of electromagnetic waves. These metasurfaces transform incident electromagnetic waves into specified reflected and…

Optics · Physics 2019-04-02 Nima Chamanara , Yousef Vahabzadeh , Christophe Caloz

Recent advances in laser technology have enabled tremendous progress in photochemistry, at the heart of which is the breaking and formation of chemical bonds. Such progress has been greatly facilitated by the development of accurate…

Space-time metamaterials are redefining wave engineering by enabling fully dynamic four-dimensional control of electromagnetic fields, allowing simultaneous manipulation of frequency, amplitude, momentum, and propagation direction. This…

Optics · Physics 2025-11-26 Sajjad Taravati

We propose a framework for designing coherent optical environments that enable versatile and dynamic optical manipulation. In contrast to conventional material-based near-field platforms, our approach employs a structured coherent light…

Optics · Physics 2025-10-07 Xiaoshu Zhao , Xu Yuan , Hongxia Zheng , Huajin Chen , Zhifang Lin

Free-space communication links are severely affected by atmospheric turbulence, which causes degradation in the transmitted signal. One of the most common solutions to overcome this is to exploit diversity. In this approach, information is…

Signal Processing · Electrical Eng. & Systems 2018-08-22 Mitchell A. Cox , Carmelo Rosales-Guzmán , Ling Cheng , Andrew Forbes

In weakly nonlinear dispersive wave systems, long-time dynamics are typically governed by time resonances, where wave phases evolve coherently due to exact frequency matching. Recent advances in spatio-temporal spectrum measurements,…

Pattern Formation and Solitons · Physics 2025-12-09 Michal Shavit , Fabio Pusateri , Zhou Zhang , Yulin Pan , Davide Maestrini , Miguel Onorato , Jalal Shatah

Orbital angular momentum (OAM) has been regarded as a potential dimension for optical communication and related fields. Despite several studies, the transmission of OAM beams through time-varying scattering media remains a challenge. In…

Optics · Physics 2026-05-08 Heshen Li , Jin Wei , Tianshun Zhang , Wen Chen

Space-time varying media enable unprecedented control over electromagnetic waves, yet most existing studies assume idealized, nondispersive materials and thus fail to capture the intrinsic frequency dispersion of realistic platforms. Here,…

Optics · Physics 2025-12-16 Klaas De Kinder , Christophe Caloz

A flexible wave localization is investigated using a spatial-temporal modulation of point defects along the periodic array of electromechanical local resonators of a piezoelectric bimorph beam. By changing the electrical resonance of…

Applied Physics · Physics 2022-02-01 Renan Lima Thomes , Danilo Beli , Carlos De Marqui

The scattering of wave packets from a single slit and a double slit with the Schr\"odinger equation, is studied numerically and theoretically. The phenomenon of diffraction of wave packets in space and time in the backward region,…

Quantum Physics · Physics 2008-11-26 G. Kälbermann

Although a plethora of techniques are now available for controlling the group velocity of an optical wave packet, there are very few options for creating accelerating or decelerating wave packets whose group velocity varies controllably…

Optics · Physics 2021-02-02 Murat Yessenov , Ayman F. Abouraddy