Researchers studying photonic crystals say they have successfully created a form of pseudogravity that bends light just like real gravity. The new technique could have a dramatic effect on advanced communication technologies like 6G, as well as other applications in optics and materials science that could benefit from a no-contact method of manipulating light.
According to the Tohoku University researchers behind the seemingly impossible accomplishment, the idea of creating pseudogravity in photonic crystals was only recently theorized. The idea, they explain in a press release announcing the breakthrough achievement, might be made possible “by deforming crystals in the lower normalized energy (or frequency) region.”
“We set out to explore whether lattice distortion in photonic crystals can produce pseudogravity effects,” said Professor Kyoko Kitamura from Tohoku University’s Graduate School of Engineering, one of the authors of the paper published in the journal Nature. That concept led them to actual experiments to see if it was possible in practice and not only in theory. The key ingredient, they say, is something called photonic crystals.
Unique Properties of Photonic Crystals Key to Pseudogravity Manipulation of Light
In their work, the researchers explain how photonic crystals have rather unique properties that allow them to manipulate and control the behavior of light, “serving as ‘traffic controllers’ for light within crystals.” In fact, photonic crystals have previously exhibited pseudogravity-like effects due to what the researchers term “adiabatic changes” in the crystals. This unique ability exists because photonic crystals are made up of two or more materials periodically arranged in a specific way that affects the flow of light in different ways. This construction, the researchers note, “allows these crystals to “interact with and slow down light in a regular, repeating pattern.”
To test their own photonic crystals to see if they could, in fact, bend light like real gravity, Kitamura’s team settled on a “silicone distorted” photonic crystal that possessed “a primal lattice constant of 200 micrometers and terahertz waves.” The team then introduced something called lattice distortion. In layman’s terms, lattice distortion is a gradual distortion of the regular spacing of the elements of the crystal, effectively disrupting the material’s typical grid-like pattern.
As hoped, this photonic band structure was just right, “resulting in a curved beam trajectory in-medium – just like a light-ray passing by a massive celestial body such as a black hole.”
“Much like gravity bends the trajectory of objects, we came up with a means to bend light within certain materials,” said Kitamura.
Breakthrough Could Improve Communication Technologies, Forge New Pathways in Graviton Physics
Although this is just a first step, the researchers behind the unique achievement say there are numerous potential applications for their light-bending pseudgravity. This includes technological applications and may even open up entirely new fields of study for physicists.
“Such in-plane beam steering within the terahertz range could be harnessed in 6G communication,” said Associate Professor Masayuki Fujita from Osaka University. “Academically, the findings show that photonic crystals could harness gravitational effects, opening new pathways within the field of graviton physics.”
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.