The history of fiber optic start In 1966, K.C. Kao, who works for the British Standard Telecommunications Experimental Ltd, together with his colleague G.A. Hockham, published a paper： “Dielectric-fibre surface waveguides for optical frequencies“.
In their paper, they propose that the attenuation of optical signals in optical fibers can be cut by reducing impurities in the glass fibers.
When the attenuation rate drops to 20 dB/km, these glass fibers could use in the area of practical communication.
This paper later became the foundation of fiber optic communication theory. It opens the door to the era of optical fiber and changes our communication technology.
End of that year in London, William Shaver visited the Post Office Research Lab.
He saw the laboratory’s introduction of the fiber optic project and felt interested in it.
At that time, William Shaver worked for Corning Incorporated as an engineer, which is the oldest glass manufacturer in the United States.
Upon returning to the United States, William Shaver reported his findings to company executives and strongly recommended that the company conduct research on optical fiber.
William Shaver’s recommendation was taken seriously by Corning Incorporated executives, and they soon launched the development of high-purity glass fibers.
Bill Armistead, Corning’s Director of Research and Development, was responsible for leading this work.
Fiber Optic Research of Corning Teams
Robert Maurer was born in 1924 and served in World War II, receiving a Purple Heart medal. After the war, he returned to university and earned a PhD in low-temperature physics from MIT before joining Corning in 1952.
It’s worth mentioning that in December 1956. He published a theoretical paper on “Glass as a Frozen Liquid” in the Journal of Chemical Physics, which was cited by K.C.Kao’s classic paper. It was one of the earliest intersections between the two.
He recruited the company’s physicist Robert Maurer and assigned him two young researchers who had just joined the company, Pete Schultz, a chemist, and Donald Keck, an experimental physicist, to form a three-person research team.
When the three-person team officially started their research, they found themselves facing a huge challenge.
At that time, the highest-purity optical fiber had an attenuation rate of about 1000 dB/km. They needed to reduce this value to 20 dB/km.
For them, there were two feasible starting plans:
first, to use a large amount of high-purity optical glass;
second, to use fused quartz (SiO2), because quartz can achieve high purity.
The first one was a more mature plan and was the plan most of their peers chose at the time. However, Robert Maurer took a different approach and chose the second plan.
SiO2 is a material with high purity. However, its melting temperature is extremely high, requiring 1650°C. The average oven cannot reach such a temperature.
After some investigation, Robert Maurer sought the help of a chemistry PhD, Frank Zimar. Frank Zimar had built an oven for Corning’s early semiconductor projects that could achieve a high temperature of 2000°C.
Early Research of team
With Frank Zimar’s help, Robert Maurer’s team pulled out the first experimental single-mode fiber in 1967, based on doped silica.
After testing, the attenuation of this fiber was still high, but it was a significant improvement compared to previous attempts. This increased the team’s confidence.
Later, through repeated trials, the research team gradually mastered the technique of drawing preforms for optical fibers. At the same time,other key technologies such as soot deposition processing.
The attenuation rate of the optical fiber they produced continued to improve, gradually approaching the theoretical value.
Born of The world’s first low-loss optical fiber
The team continued their research in secrecy. In May 1970, Corning Inc. applied for two patents based on their findings.
The first patent was for a fused quartz optical waveguide, designed by Maurer and Schultz, which made with pure quartz cladding and doped quartz core.
The second patent, by Keck and Schultz, was for a method of producing optical waveguide fibers, which cover the later-known process of inside vapor deposition (IVD).
In July 1970, the team pulled six fibers from preforms containing six different titanium-doped silica core glasses. On August 7th, they tested a 29-meter fiber and achieved a loss of 17 dB/km, which was the first time reach the goal of 20 dB/km. Keck excitedly recorded the result in his notebook, writing “Whoopee!”.
To ensure accuracy, the team pulled a 210-meter fiber on August 21st and tested it. When Keck’s helium-neon laser entered the fiber’s core, he was surprised to see a very bright red flash from the far end, which he realized was a reflection from the fiber’s end-face. The measured loss of this fiber was 16.9 dB/km.
In late September 1970, Maurer flew to London to present the team’s research findings at the Institution of Electrical Engineers Symposium on Optical Fiber Communication, causing a sensation in the industry. Later, the British Post Office Laboratories and Standard Telecommunication Laboratories tested Corning’s fibers and confirmed their results.
Despite the success, Corning’s fibers were not immediately commercially available as they still had technical issues with the use of titanium-doped cores.
Fiber optical technology for practical applications
It wasn’t until June 1972, when Corning used germanium-doped cores and the outside vapor deposition (OVD) process, that they produced a multi-mode fiber with a loss as low as 4 dB/km. This new fiber had lower loss, higher practicality, and simpler production process.
In the later years, due to the economic recession, Corning faced some challenges in promoting the commercialization of their fiber optic technology.
To raise funds, Chuck Lucy, the head of Corning’s fiber optic business, negotiated with several telecommunications companies and signed joint development agreements to share the development costs.
These agreements accelerated the commercialization of fiber optic technology. In 1976, American Telephone and Telegraph Company (AT&T) installed the world’s first experimental fiber optic communication system in Atlanta, which was about 1.25 miles (approximately 2000 meters) long.
Three years later, in 1979, Nippon Telegraph and Telephone Corporation (NTT) developed a low-loss quartz fiber with an attenuation value of 0.2 dB/km, which was close to the theoretical scattering limit.
In 1980, the Winter Olympics in Lake Placid successfully transmitted television signals using fiber optic cables for the first time, achieving great success.
Optical fiber nowdays
As time went on, fiber optics became more familiar to everyone.
In the 1980s and 1990s, optical fiber technology quickly emerged as an important transmission medium in wired communication.
In the 21st century, optical fiber completely replaced metal cables. It becomes the backbone of the entire communication network.
The amount of data that can be transmitted by a single optical fiber has long surpassed the level of terabits per second.
Today, the global demand for optical cables exceeds 500 million fiber kilometers per year.
These optical fibers transmit massive amounts of data, support the development of society and make huge contribution to human civilization.
