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.

Published in Nature, this breakthrough uses HZDR’s TELBE superradiant terahertz source to drive the system into a new regime of light-matter interaction in the terahertz range. This discovery paves the way for ultrafast optical computing, new telecommunications systems and eventually new types of terahertz lasers.

Shaping the properties of light as it interacts with materials is the foundation of many discoveries and technological advances, including optical fibers for telecommunications, lasers as light sources and sensors for chemistry and biology.