Time-varying media have recently emerged as a new paradigm for wave manipulation, due
to the synergy between the discovery of highly nonlinear materials, such as epsilon-near …

Recent progress in nanophotonics and material science has inspired a strong interest in
optically-induced material dynamics, opening new research directions in the distinct fields of …

The law of reciprocity in acoustics and elastodynamics codifies a relation of symmetry
between action and reaction in fluids and solids. In its simplest form, it states that the …

Photonic time crystals (PTCs), materials with a dielectric permittivity that is modulated
periodically in time, offer new concepts in light manipulation. We study theoretically the …

Time reflection is a uniform inversion of the temporal evolution of a signal, which arises
when an abrupt change in the properties of the host material occurs uniformly in space. At …

BACKGROUND Metasurfaces have opened up a number of remarkable new approaches to
manipulate light. These flat optical elements are constructed from a dense array of strongly …

Metamaterials are rationally designed composites aiming at effective material parameters
that go beyond those of the ingredient materials. For example, negative metamaterial …

Deflecting and changing the direction of propagation of electromagnetic waves are needed
in multiple applications, such as in lens–antenna systems, point-to-point communications …

The overall article presents the authors' vision of the emerging field of spacetime
metamaterials, and related systems, in a cohesive and pedagogical perspective …

For optics, like semiconductor heterostructures, the interfaces and inhomogeneities in
materials can manipulate optical waves and fields. Numerous photonic devices and …