Remembering Narinder Kapany, the “Father of Fiber Optics”

January 11, 2021 by Adrian Gibbons

Coining the term "fiber optics" in 1955, physicist Narinder S. Kapany conducted research that had resounding effects across multiple disciplines, including electrical engineering. 

On December 3rd, 2020, physicist Dr. Narinder S. Kapany—known as the "father of fiber optics"— passed away at the age of 94 in Woodside, California, surrounded by his family.


Dr. Narinder S. Kapany

Dr. Narinder S. Kapany (1926–2020) in a lab at Imperial College London. Image used courtesy of Joseph McKeown and The New York Times

Kapany was a polymath in the proper sense of the word with achievements in academia, cultural philanthropy, entrepreneurship, and physics. Although Kapany himself was a physicist, his work has had resounding effects across multiple disciplines, including electrical engineering. 

Although Shanghai-born scientist Charles Kuen Kao is often credited with the most significant breakthroughs in fiber optics, winning him the 2009 Nobel Prize in Physics, it was Kapany who first transmitted images over a bundle of optic fibers 12 years prior.  


From Academic to Entrepreneur

Born October 31, 1926, in Punjab-India, Kapany traveled around the world throughout his life for both academic and entrepreneurial purposes. 

In 1948, Dr. Kapany earned his undergraduate degree in physics at the Agra University in India with a doctorate to follow in 1955 from Imperial College London. Transitioning from student to professor, Dr. Kapany spent many years teaching at various universities, including Rochester University and the Illinois Institute of Technology in Chicago. 

After moving to California in 1961, Dr. Kapany founded the Center for Innovation and Entrepreneurial Development at the University of California Santa Cruz and was awarded several additional academic accolades from UC Berkeley and Stanford University.

His scientific achievements in photonics paved the way for the modern communication infrastructure of the internet and cellular networks.


How Kapany Bent Light

Early in his college career, one of Kapany's professors claimed that light only traveled in a straight line—an assertion that Kapany questioned for years. Then, in 1954, Kapany teamed up with his advisor Dr. Harold Hopkins to bend light for the first time with the invention of the glass cable, later termed fiber optics. 

In an article published in Nature, Hopkins and Kapany outlined how they used a 75-centimeter bundle of several thousand optical fibers to achieve low-loss light transmission.


A signal made of light traveling down a glass optic confined by cladding

A signal made of light traveling down a glass optic confined by cladding. Image used courtesy of     


"Dr. Hopkins suggested that I try glass cylinders instead of prisms," Kapany explained to author Shivanand Kanavi for the novel "Sand to Silicon: The Amazing Story of Digital Technology."

"So, I thought of a bundle of thin glass fibres, which could be bent easily."

While Kapany's initial research interest was to improve medical imaging devices, he eventually came to see the broad applicability of fiber optic communication in 1955 when he coined the term. Because of Kapany's work, we understand that light can in fact bend and that the principle of reflected light is the basis for all long-distance, low-loss optical communications. 


Researchers Build on Kapany's Findings

While Kapany may have kicked off the era of fiber optics communication, there were certainly many practical kinks to work out in its implementation. For one, optical glass fiber often lost signal over long distances. Kapany's first cable, for instance, could only transmit light over 9 meters before it dissipated. Dr. Charles Kuen Kao remedied this issue by calculating how to transmit light over expansive distances, leading to the first "ultrapure fiber" in 1970. 

Today, fiber optics is the most common material in telecommunications because of its resistance, weight, and flexibility. Fiber optic research took off after Kapany and Hopkins published their 1954 research, which drove Kapany to publish a staple in the field of optics, "Optical Fibres: Principles and Applications" (1967). 


Fiber Optics Beyond Telecom

As much as 95% of Internet traffic is transmitted via submarine cables made of optical fibers, according to OpenMind BBVA. Beyond telecommunications, Dr. Kapany’s invention of the fiber optic cable has led to other areas of research, such as the optogenetic stimulus of memory centers in the brain of a mouse at Tonegawa Lab, MIT.


Susumu Tonegawa’s research into memory alteration and activation using optogenetics

Susumu Tonegawa’s research into memory alteration and activation using optogenetics. Image used courtesy of OpenMind BBVA


Kapany's contributions, combined with the work of subsequent researchers, have also led to significant developments in bronchoscopy, laryngoscopy, and laparoscopy. The technology he kickstarted is also commonly found in sensors measuring pressure, voltage, and temperature. Recent research has even tapped fiber-optic technology to efficiently capture solar energy.


Kapany's Lasting Legacy

Dr. Kapany was a consummate entrepreneur, founding no less than three companies focused on optical technology and solar technology over the course of nearly forty years. By the time he passed in his mid-90s, he had patented over 100 technologies and spearheaded the Sikh Foundation, a philanthropic organization that aims to bridge the Sikh community and others across the United States. 



In what ways have the seeds of Kapany's work had a residual effect on your day-to-day engineering practices? Share your thoughts in the comments below.