Photonic time crystals unlock ultrafast control of light in the terahertz range

An international team of researchers from École Polytechnique, Collège de France and Helmholtz-Zentrum Dresden-Rossendorf (HZDR) has achieved a world first: the experimental realization of an all-optical photonic time crystal (PTC), a material whose optical properties can be strongly and periodically modulated over ultrafast timescales.