Researchers at the University of Michigan have discovered a novel way to generate bright, twisted light—known as chiral light—using technology reminiscent of Thomas Edison’s Lightbulb.
The results, published in a recent issue of Science, help advance our understanding of fundamental physics and pave the way for applications in robotic vision systems and other cutting-edge technologies.
“It’s hard to generate enough brightness when producing twisted light with traditional ways like electron or photon luminescence,” Jun Lu, the study’s lead author and an adjunct chemical engineering researcher at U-M said in a recent statement. “We gradually noticed that we actually have a very old way to generate these photons—not relying on photon and electron excitations, but like the bulb Edison developed.”
The Twisted Light of Edison’s Lightbulb
Twisted light traces a helical path through space, with its waves oscillating in a corkscrew motion. This quality, also called chirality, can distinguish objects based on the unique twists of light they emit or reflect. Chiral light is important in advanced imaging and sensing technologies, including systems that could help autonomous vehicles or robots differentiate between objects in their surroundings.
Traditionally, generating twisted light has been challenging due to low brightness. The Michigan team’s innovation resolves this by revisiting a classic concept: blackbody radiation, the type of light emitted by any warm object, including Edison’s tungsten light bulb.
Diving Into Blackbody Radiation
Blackbody radiation typically emits a broad spectrum of light, which appears white to the human eye. However, the shape of the emitter at the micro or nanoscale can alter the light’s polarization—the orientation of its oscillations. The researchers found that when the emitter was twisted at a scale comparable to the wavelength of the emitted light, the resulting blackbody radiation became chiral, with twisted photons.
“Such emitters are everywhere around us,” Nicholas Kotov, the Irving Langmuir Distinguished Professor of Chemical Sciences and Engineering at U-M and the study’s corresponding author, noted in a recent statement. “These findings, for example, could be important for an autonomous vehicle to tell the difference between a deer and a human, which emit light with similar wavelengths but different helicity because deer fur has a different curl from our fabric.”
Twisting Light to Become Even Brighter
The key advantage of this approach is brightness—twisted light produced with this method is up to 100 times brighter than with traditional techniques. This makes it particularly promising for applications like robotic vision and autonomous vehicles, where distinguishing objects in complex environments is crucial.
The team envisions robots and self-driving cars equipped with sensors capable of seeing like mantis shrimp, which can differentiate between various types of twisted light. For example, these systems could use the unique twists of light emitted by different materials to identify obstacles or living creatures.
While this discovery is a significant step forward, challenges remain. The generated light includes a broad spectrum of wavelengths and twists, complicating practical applications. The researchers are exploring ways to refine the technology, including the possibility of developing lasers that emit precisely tuned twisted light.
The findings offer a glimpse into a future where technology rooted in a 19th-century invention transforms robotics, imaging, and more.
As Kotov puts it in the statement, “The advancements in the physics of blackbody radiation by chiral nanostructures are central to this study, opening doors to exciting new applications.”
Kenna Hughes-Castleberry is the Science Communicator at JILA (a world-leading physics research institute) and a science writer at The Debrief. Follow and connect with her on BlueSky or contact her via email at kenna@thedebrief.org