Scientists have created photonic time crystals, unique materials that amplify light and can improve the performance of lasers, sensors and communications technologies. These crystals exhibit oscillations over time that allow exponential amplification of light, and their potential applications range from enhanced sensing to communications.

Photonic time crystals

Scientists have successfully developed realistic photonic time crystals, exotic materials that can exponentially amplify light. This breakthrough by an international team of researchers opens up transformative possibilities in areas such as communications, imaging and sensing, paving the way for faster and more compact lasers, sensors and other optical technologies.

“This work could lead to the first experimental realization of photonic time crystals, bringing them to practical applications and potentially transforming the field,” says Associate Professor Viktor Asadchy from Aalto University, Finland. “From high-efficiency light amplifiers and advanced sensors to innovative laser technologies, this research pushes the boundaries of how we can control the interaction of light and matter.”

Understanding and Using Time Crystals

Photonic time crystals are a unique type of optical material. Unlike conventional crystals, which have structures that repeat in space, these crystals remain spatially uniform but oscillate periodically over time. This property creates “impact slits”, unusual states in which light is effectively stopped within the crystal and its intensity increases exponentially. To illustrate this extraordinary interaction, imagine light traveling through a medium that switches between air and water a quadrillion times per second; This is a phenomenon that challenges traditional understanding of optics and opens up new possibilities.

One potential application of photonic time crystals is nanosensors.

“Imagine that we want to detect the presence of a tiny particle, such as a virus, a pollutant, or a biomarker of diseases such as cancer. When excited, this particle emits a very small amount of light at a specific wavelength. A photonic time crystal can capture this light and automatically amplify it, making it more efficient with existing equipment.” It may enable detection in some way,” says Asadchi.

Overcoming technical difficulties

Creating photonic time crystals for visible light has long been a difficult task due to the need for extremely fast and also large amplitude changes in material properties. To date, the most advanced experimental demonstration of photonic time crystals, developed by members of the same research group, has been limited to much lower frequencies, such as microwaves.

In their latest work, the team proposes the first practical approach to creating “true optical” photonic time crystals using theoretical models and electromagnetic simulations. By using an array of tiny silicon spheres, they envision that the special conditions needed to amplify light that were previously unattainable could finally be achieved in the laboratory using known optical techniques.