Ming-Jun Li is a co-inventor of the bend-insensitive ClearCurve® optical fiber. This breakthrough technology can bend without causing significant signal loss, allowing it to reach more locations and provide greater bandwidth with fiber-to-the-home applications. In recognition of this invention, which has advanced data transmission across many industries, Li and his colleagues, Dana Bookbinder and Pushkar Tandon, will join the National Inventors Hall of Fame® (NIHF) as members of our 2020 Inductee class.
An Unconventional Path
Li was born in Beijing, China, in 1959. During his childhood, he experienced food scarcity and a delay in the start of his education due to China’s Cultural Revolution. He entered elementary school at age 8 and recalls that exposure to typical academic subjects beyond language and mathematics was limited at that time.
While in high school, Li became interested in science. However, when he prepared to enter a university, he did not choose just one field on which to focus, as we might expect. Instead, he explains, when registering to take China’s National College Entrance Examination (NCEE), students were asked to select five universities, and Li chose a different major for each of his five selections. This approach meant that he could follow the course of study that was considered a specialty of each individual university. So, for instance, had Li been accepted into Tsinghua University, he would have studied architecture.
Li was accepted by Beijing Institute of Technology, where he chose to major in physics. When Li was admitted to this school in 1979, just 6% of applicants were accepted. After earning his bachelor of science degree in applied physics in Beijing, Li completed his graduate studies in France. He earned his master of science degree in optics and signal processing at the University of Franche-Comté and his doctorate in physics at the University of Nice.
Li began working for Corning Incorporated — in what he’d described as his dream job — in 1994. It was here that he began working with Bookbinder and Tandon, and the team conducted experiments with optical fiber. “Optical fiber is so thin,” Li shared in an interview with NIHF. “The diameter is like a human hair. And the light can go through that thin glass for hundreds to thousands of kilometers — to me that was magic.”
Before the emergence of optical fiber, copper wire was used to transmit phone calls and data over long distances. While copper uses electric current, optical fiber sends pulses of light. Conventional optical fiber required long, straight cables to transmit data without significant signal loss, and it could not transmit light around tight bends. In 2004, Li, Bookbinder and Tandon discovered that certain types of optical fiber could transmit light around tight bends when they explored wrapping the material around a cylindrical rod. The light continued traveling through the fiber and out the other end.
Eventually, the trio created a fiber that caused light beams to be reflected smoothly back into the core rather than diffracted in the cladding at a sharp bend. Introduced by Corning in 2007, this new bend-insensitive fiber had a core surrounded with a low refractive index “optical trench.” The fiber structure was optimized for both single-mode fiber and high-bandwidth multimode fibers that were fully standards-compliant for fiber-to-the-home and data center applications.
Li says that bend-insensitive optical fiber “can make the optical communication system better, and also make people’s lives better. When any fiber is used for that, I always feel very good about it and I’m very proud of that.”
Ming-Jun Li holds more than 200 U.S. patents and is a Corning Corporate Fellow. He will be formally Inducted along with our entire class of 2020 NIHF Inductees at the NIHF Induction Ceremony. To find more blogs introducing our inspiring 2020 Inductees, visit invent.org.