Time-varying media have recently emerged as a new paradigm for wave manipulation, thanks to thesynergy between the discovery of novel, highly nonlinear materials, such epsilon-near-zero and questfor novel applications, magnet-free nonreciprocity, multi-mode light shaping, ultrafast switching. Inthis review we provide comprehensive discussion recent progress achieved with photonic metamaterials whoseproperties stem from their modulation in time. We basic concepts underpinning temporal...

Abstract Recent progress in nanophotonics and material science has inspired a strong interest optically-induced dynamics, opening new research directions the distinct fields of Floquet matter time metamaterials. phenomena are historically rooted condensed community, as they exploit periodic temporal drives to unveil novel phases matter, unavailable systems at equilibrium. In parallel, field metamaterials been offering platform for exotic wave based on tailored materials nanoscale, recently...

Temporal interfaces introduced by abrupt switching of the constitutive parameters unbounded media enable unusual wave phenomena. So far, their explorations have been mostly limited to lossless media. Yet, non-Hermitian phenomena leveraging material loss and gain, balanced combination in parity-time (PT)-symmetric systems, opening new vistas photonics. Here, we unveil role that temporal offer physics, introducing dual PT symmetry for boundaries. Our findings reveal unexplored interference...

Nonreciprocity is critically important in modern wave technologies, yet its general principles and practical implementations continue to raise intense research interest, particular the context of broken reciprocity based on spatiotemporal modulation. Abrupt changes time electromagnetic properties a material have also been shown replace spatial boundaries, supporting highly unusual wave-matter interactions so-called metamaterials. Here, we introduce nonreciprocity for temporal demonstrating...

Time metamaterials offer a great potential for wave manipulation, drawing increasing attention in recent years. Here, we explore the exotic dynamics of an anisotropic photonic time crystal (APTC) formed by medium whose optical properties are uniformly and periodically changed time. Based on temporal transfer matrix formalism, show that stationary charge embedded APTC emits radiation, contrast to case isotropic crystals, its distribution momentum space is controlled band structure. Our...

Temporal metamaterials have been recently exploited as a novel platform for conceiving several electromagnetic and optical devices based on the anomalous scattering response arising at single change or multiple sudden changes in material properties. However, they are difficult to implement realistic scenarios by switching permittivity of time, new strategies achieve time interfaces feasible manner must be identified. In this paper, we investigate possibility realize temporal metamaterial...

Abstract The advent of novel nonlinear materials has stirred unprecedented interest in exploring the use temporal inhomogeneities to achieve forms wave control, amidst greater vision engineering metamaterials across both space and time. When properties an unbounded medium are abruptly switched time, propagating waves efficiently converted different frequencies, partially coupled their back-propagating phase-conjugate partners, through a process called time-reversal. However, realistic...

Temporal interfaces, arising when the electromagnetic properties of a medium are abruptly switched in time, have been recently raising interest as dual spatial interfaces. Their study has mostly focused on switching time infinite media, for which wave momentum is conserved, yielding phenomenon interfaces at frequency conserved. Here, we demonstrate interesting phenomena temporal they involve finite-size resonant structures. By changing permittivity grounded dielectric slab supporting strong...

Time-interfaces, at which the optical properties of a medium undergo abrupt and spatially uniform changes, have attracted surging interest in optics wave physics. In this work, we study scattering time-interfaces involving chiral media. Dual to spatial interfaces media, show that propagating is split upon time-interface into two orthogonal circular polarization waves oscillating different frequencies. We formulate temporal boundary-value problem such time-interfaces, then demonstrate effect...

Recent years have witnessed a surge of interest in exotic electromagnetic (EM) wave propagation time-varying systems. An interesting concept is the one temporal interface, time-analogue spatial formed by an abrupt and uniform change EM properties host medium time. A time interface scatters incident dual fashion compared to its counterpart, conserving momentum but transforming frequency exchanging energy with wave. This article provides overview wave-scattering features induced interfaces...

Brewster effect has attracted extensive interests through microwave to optical regime. However, previous work mainly focused on the cases with single linear polarization. We demonstrate in this paper an equal Brewster's angle for both TE (transverse-electric) and TM (transverse-magnetic) waves. Tunable is furthermore achieved. For practical implementation of effect, we propose anisotropic metagrating composed modified split ring resonators (MSRR) as a proof-of-concept X-band. Measurement...

Time-reflection is a uniform inversion of the temporal evolution signal, which arises when an abrupt change in properties host material occurs uniformly space. At such time-interface, portion input signal time-reversed, and its frequency spectrum homogeneously translated while momentum conserved, forming counterpart spatial interface. Combinations time-interfaces, time-metamaterials Floquet matter, exploit interference multiple time-reflections for extreme wave manipulation, leveraging time...

We show, semi-analytically and numerically, how the relativistic accelerated motion of a waveguide’s parallel plates induces fast mode conversion including reflection, similar to temporal interface by sudden variation interplate distance through conductivity switching.

Exotic forms of wave control have been emerging by engineering matter in space and time. In this framework, temporal photonic interfaces, i.e., abrupt changes the electromagnetic properties a material, shown to induce scattering phenomena dual spatial reflection refraction, at basis time crystals space-time metamaterials. Despite decades-old theoretical studies on these topics, recent experimental demonstrations, careful modeling has lagging behind. Here, we develop from first principles...

Coherent wave control exploits the interference among multiple waves impinging on a system to suppress or enhance outgoing signals based their relative phase and amplitude. This process inherently requires non-Hermiticity, in order enable energy exchanges waves, spatial interfaces tailor scattering. Here we explore temporal analogue of this phenomenon, time-interfaces that support instantaneous non-Hermitian scattering events for photons analogous mechanical collisions. Based mechanism,...

Periodic arrays can support highly nontrivial modal dispersion, stemming from the interplay between localized resonances of array elements and distributed supported by lattice. Recently, intentional defects in periodicity, i.e., broken

We experimentally demonstrate chaotic coherent perfect absorption states, as well their non-Hermitian degeneracies in a optical microresonator supporting more than 1000 modes.