How It Works: Fibrance Light-Diffusing Fiber | Science of Glass | The Glass Age | Corning

Fibrance technology is basically a glass optical fiber that unleashes colorful lighting. Yet, to really understand it, you have to go back to the beginning when a Corning team uncovered how a fiber leak could become an innovation.   

“We were researching how to minimize any losses of light from bending Corning^® ClearCurve^® optical fiber by modifying the refractive index of the optical fiber clad – in other words the outer layer ‒ with small inclusions called optical nanostructures,” said Stephan Logunov, Senior Research Associate. The refractive index is a ratio to determine of how light is bent, or refracted, when entering a material like optical fiber.

“This approach helps contain the light traveling through the fiber especially when it is bent, but when we added nanostructures into the inner core of the fiber instead of the cladding, it created a totally different effect – the light was actually scattering, or leaking, from the fiber.”

Logunov explained that while Fibrance technology was a bit of an accidental discovery, researchers invented the technology with the same process – something called outside-vapor deposition ‒ used to manufacture traditional fiber. Fibrance technology has the thinness and flexibility of optical fiber, but creates a whole new experience with how it handles light.  

“Just by tweaking the material before the fiber is drawn into thin strands of glass, the silica is infused with optical nanostructures that emit or ‘leak’ light versus controlling it,” he said.

When light hits these nanostructures it evenly emits or diffuses the light out of the sides, but also down the length of the fiber.

Fibrance technology differs from optical fiber for the telecommunications industry which is designed to have very low losses of data signals in form of light. The light refracts and travels within the fiber’s core in order to transmit data signals that enable the high-speed downloads and bandwidth we expect every day.

While Fibrance technology may seem like a dripping faucet of light, Corning researchers have figured out how to tailor the light into a controlled, steady stream.

"It may have started as a leaky fiber, but we know how to fine tune that light and the diffusion length so the fiber stays bright; how to pair the fiber with the proper light-sources to create new lighting effects; and how to integrate, embed, or stitch the fiber into our customers’ latest products and design projects,” said Carl Crossland, program manager for Fibrance technology, Advanced Optics, Corning Specialty Materials.

To emit light, the fiber must be connected to a source, but not just any old light bulb will work. The Fibrance technology team recommends a laser diode.

Vineet Tyagi, commercial lead, Fibrance technology, Advanced Optics, Corning Specialty Materials, explained that laser diodes have the best numerical aperture to illuminate the fiber.

“Basically that means the laser diode is very pointed, direct, and powerful enough to push the right amount of light into the fiber,” Tyagi said.

There’s more to the Fibrance technology than just a bright strand of light. When it is connected to a laser, the fiber becomes almost like a painter’s palette with how accurately and beautifully it blends and mixes colors together.

Tyagi explained that the fiber gets its colors from one or more lasers. For example, when one fiber is connected to a blue laser on one end, and a red laser on the other, the result is a striking purple with shades of electric pink and blue. Lastly, because the fiber is made of optically pure glass, it produces true, bright colors.

“Similar to paint mixing, when you couple the fiber to the right light source, it creates new colors, new effects, and nearly unlimited design possibilities,” said Tyagi. 

That mixture of color goes on full display in a recently introduced set of smart headphones illuminated by Fibrance technology and state-of-the-art lasers. The headphones, manufactured by a company aptly named Glow, sync to your music amid hues of red, blue, or green. Other customers in the consumer electronics, automotive, architecture, and design worlds are also coming on board with their own innovations using Fibrance technology.

“We could not have predicted that our discovery of a light-diffusing fiber would lead to a whole new product and business opportunity for Corning,” Logunov said. “The future for Fibrance technology is very exciting.”