Overview
- A multi‑institution team from École Polytechnique, Collège de France and HZDR reported in Nature in late July the first experimental all‑optical photonic time crystal that modulates optical properties in time rather than space.
- The device is a plasmonic metamaterial of micrometer‑scale gold crenellations above an insulating layer and an indium‑antimony semiconductor that traps light and supports surface plasmons.
- High‑field, phase‑stable terahertz pulses from HZDR’s TELBE source produced strong, repeating temporal changes on picosecond timescales that alter reflectivity and resonance frequency.
- A theoretical model by Marco Schiró’s team reproduced the observations and the time modulation was measured to cut photon dissipation inside the device by roughly 50 percent.
- Researchers say the next goals are to lower remaining losses and amplify trapped photons to reach sufficient gain for tunable terahertz lasers, with longer‑term uses envisioned in ultrafast optical computing, communications and medical imaging.