- Physicists distorted a type of material known as a photonic crystal—as described in Einstein’s theory of general relativity—to deflect the path of light as if it were passing through a gravitational field.
- The result has implications for the control of light, especially as it relates to optics and communications technology, according to a team led by electronics engineer Kanji Nanjyo of the Kyoto Institute of Technology.
- The findings could advance 6G communications research.
“We set out to investigate whether lattice distortion in photonic crystals could create so-called gravitational effects,” said Professor Kyoko Kitamura of Tohoku University. says.
“Just as gravity bends the orbit of objects, we have found a way to bend light within certain materials.”
In theory, any object with mass should affect the path of light. We can see this effect when we look at the cosmos; Massive objects such as galaxies and galaxy clusters bend space-time so significantly that any light passing through them is scattered and distorted.
As objects become smaller in size, the weakness of gravity becomes more apparent and distortion effects become harder to observe.
Scientists thought they could replicate this effect on a smaller scale using photonic crystals. These crystals are highly ordered and repeating nanostructures in which the refractive index of light changes periodically, creating an iridescent effect; examples in nature include opals, peacock feathers, and the shimmering wings of butterflies.
It’s relatively easy to create these crystals artificially by arranging two different materials that interact with light differently. Scientists have previously noted that crystals can serve as an analogy for space-time, with their structure representing a path known as a geodesic. As light passes through its structure, the normally straight path of light can become distorted, such that light can bend in space in what is described as a type of pseudogravity.
Researchers have attempted to create and manipulate photonic crystal “pseudogravity” by experimentally distorting photonic crystals. They created silicon photonic crystals and created distortion by deforming the space between rows of elements.
This changed the way the crystal interacted with light, producing a curved beam like light passing around a small black hole.
Experiments in which they passed a beam through a crystal and observed how and where it emerged confirmed the team’s efforts. The team says this could help study gravity, a phenomenon we still don’t fully understand, but also has implications for technology development.
“This type of in-plane beam steering in the terahertz range can be used in 6G communications,” said physicist Masayuki Fujita from Osaka University. Academically, the findings show that photonic crystals can harness the effects of gravity and open new avenues in the field of graviton physics.” The research he said Physical Review A It was published in the magazine.
Compiled by: Görkem Süner