Physicists in Paris have fabricated the world’s first temporal photonic crystal, adding a new dimension to humanity’s quest to control light by utilizing time itself, according to a recent paper published in Nature on July 29, 2026. Yannis Laplace led the team at the Laboratory of Irradiated Solids (LSI) alongside other European institutions to demonstrate the device, which controls light over time without expending energy when hit by terahertz electromagnetic waves.
How Temporal Photonic Crystals Modulate Light
Controlling the properties of light for applications in telecommunications, sensors, and light sources relies heavily on crystals, which are regularly and periodically organized systems that can be constructed of gas, liquids, or translucent matter. Photonic crystals emerged in the 1980s with alternating materials that each had unique effects on photons, giving rise to modern lasers, optical fibers, and photodetectors. The LSI team combined photonic crystals with time crystals to develop a temporal photonic crystal, successfully moving the concept from theory into physical reality, according to findings published in Nature.
It consists of micrometer-scale gold structures shaped like battlements with open cavities separated from an indium-antimony semiconductor by an insulating layer, trapping light photons in the cavities between the gold structures.
Did you know? Traditional photonic crystals alter light across space using physical structures, but temporal photonic crystals modulate light across time without requiring external energy to drive the process.
Testing and Observing Plasmon Oscillations
To demonstrate the device in a real-world setting, the LSI team bombarded it with terahertz laser pulses and recorded the material’s optical properties as it modulated light over time. The effect produced a strong modulation that alternated one billionth of a billionth of a second, according to experimental data. At the semiconductor layer, researchers observed electrons forming from light waves in surface plasmons, oscillating with their effective mass as greater speeds made the electrons heavier to produce optical modulations.
Indirect evidence suggests that photons trapped inside the structure are amplified, although researchers have not yet made direct observations confirming the process, according to the LSI team. Experiments are ongoing as the group attempts to capture the photon trapping phenomenon directly. Laplace and his colleagues view these time crystals as a pathway toward terahertz-scale light sources and detectors that will bridge the gap between electronics and visible light frequencies.
Frequently Asked Questions
What is a temporal photonic crystal?
A temporal photonic crystal is a device that controls light-matter interactions by alternating its optical properties over time rather than just across physical space, operating in the high terahertz range.
Who led the development of the temporal photonic crystal?
Yannis Laplace led the research team at the Laboratory of Irradiated Solids (LSI) in Paris, with assistance from other European institutions.
When was the discovery published?
The research paper titled “Plasmonic Metamaterial Time Crystal” was published in Nature on July 29, 2026.
What are the potential applications of this technology?
Researchers expect the technology to lead to terahertz-scale light sources and detectors, along with advancements in telecommunications and sensors.
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