Refractive index - the ratio of the speed of electromagnetic radiation in a medium to its speed in a vacuum - can be modulated fast enough to generate photonic time crystals (PTCs) in the near-visible ...

When we think about highly sensitive medical testing, we often imagine a hospital laboratory filled with large instruments, trained technicians, and carefully controlled conditions. This is especially ...

Scientists have demonstrated that negative refraction can be achieved using atomic arrays -- without the need for artificially manufactured metamaterials. Scientists have long sought to control light ...

PTCs, materials in which refractive index rises and falls rapidly in time, are the temporal equivalent of photonic crystals in which the refractive index oscillates periodically in space causing, for ...