In my previous blog series, I wrote about Sweden’s Forgotten WDM Breakthrough. Due to an unfortunate decision over which I had no control, I was forced to put the project on hold for the time being.

Survival

Back in 1988, I had no doubt that Wavelength Division Multiplexing (WDM) for fiber-optic networks would eventually catch on. The industry assumed this would happen once network traffic became so heavy that it would be necessary to increase capacity by adding multiple channels to each fiber in the cables.

I wasn't just thinking of that particular application. There were—and still are—many more. At the time, I had twelve years of experience in fiber optics and photonics, ten of which were with WDM technology.

The transmitters were the most important modules in those systems. I held patents for them in several countries. The U.S. patent was the most important one. It was granted in 1989 after a great deal of work, as it was considered strong and covered a broad field.

Unfortunately, the costs had also become very high. I was in contact with a small Canadian company that manufactured fiber-optic components. The founders had a similar background to mine. They faced the same problems. Their solution was not to patent their technology but instead to stay ahead of the curve in terms of development.

Our clients were generally large organizations. They had the money, but very often not the edge needed to stay ahead of the competition. There was a sense of cutthroat behavior among them; they simply steamrolled small companies like ours and didn’t care if they were infringing on our rights. They knew we didn’t have the resources to successfully take them to court.

For me, it was a matter of finding a way to make ends meet so I could help support my family, while at the same time safeguarding BOH Optical AB’s expertise—and especially its WDM technology—for the future. I continued my scientific work at that company, which at the time had no employees. 

The solution was to start a new company and act as an importer in the Nordic market. The company focused on fiber-optic products from leading foreign manufacturers. It was founded in 1988 together with two partners: an industry expert and a banker. The company was named Scan Fiber Opto AB.

I had been in contact for some time with Professor and electrical engineer Alec Gambling, who was based in England. He was well known internationally and a co-founder of a company that was a world leader in the field.

The company manufactured fiber-optic measuring instruments and accessories. The most advanced models cost up to five-digit figure amounts in euros. Those sales, a new concept for access networks including revolutionary connectors and ribbon fiber from Japan, as well as components from the Canadian company, became the core of the new company’s operations.

Professor Alec Gambling

Before I continue, I’d like to tell you more about BT Professor of Optical Communication at University of Southampton William Alexander Gambling (1926–2021), Alec Gambling, for short. The “BT” stands for the fact that he held a professorship sponsored by British Telecom.

He was one of the early pioneers in fiber optics. I first became aware of Professor Gambling’s work while conducting science in that field at the Royal Institute of Technology (KTH) in Stockholm, Sweden. At that time, the focus was on theory and measurement technology. When I came into direct contact with him, we hit it off immediately. We usually met in connection with conferences we both attended.

Among his many important contributions to the industry, I would like to highlight that he was the founder and director of the Optoelectronics Research Centre from 1989 to 1995. Later, he served as director of Research and Development at Optoelectronics LTH Industries Ltd from 2002 to 2007.

Dr. Charles Kao

The crucial basic research in fiber optics was conducted in England in the 1960s. Professor Gambling was on the right track early on, but before him came Sir Charles Kuen Kao (1933–2018), a Ph.D. and electrical engineer. In the 1960s, he worked at Standard Telecommunication Laboratories. It was the Standard Telephones and Cables (STC) research center in Harlow.

Much later, I visited the laboratory. Dr. Kao had left and worked someplace else. It turned out that the name Bengt Hallberg from Sweden was a well-known name among the scientists there. The first question I was asked was whether I played the piano. Unfortunately not, I replied. It turned out that the scientists considered my namesake in Sweden—the composer and jazz pianist—to be a towering figure.

When I search online for pictures of the building that housed the lab, I can’t find any. I remember it as a military hangar from the World War II era. There were reportedly several RAF airfields near Harlow. It must have been close to one of them. They told me that a fox had once gotten into the lab and run around causing a commotion.

Aside from being a pleasant visit, we didn’t get much out of it from a purely scientific standpoint, as far as I can recall. My expertise was on WDM technology at the time, and they were working in other scientific fields.

Dr. Kao became famous for formulating a key hypothesis that it was the purity of the glass—and not the physics—that was the limiting factor for optical fibers. If the impurities could be removed, it would be possible to achieve an attenuation of less than 20 dB/km (decibels per kilometer, a measure of the attenuation of a signal over a distance). This was considered a threshold value for optical fibers to be competitive with conventional telecom technology using metallic wires.

The paper was published in 1966 together with his colleague Dr. George A. Hockham. He traveled around globally to generate interest in his basic research, but he had a hard time getting any positive response from the outside world at first. I can relate to and understand his dilemma. I had experienced the same thing in my field of expertise.

Dr. Kao was in a more difficult situation than I was, since he had no method for manufacturing optical fibers to demonstrate at that time. The solution came in 1970 when scinentists at Corning Glass Works in the U.S. succeeded in developing a method for manufacturing the first low-loss optical fiber. Various technologies were then developed around the world during the rest of that decade.

Dr. Kao received the Nobel Prize in Physics in 2009 for his significant contribution. The Nobel Prize Award Ceremony is held on December 10 every year, but before that, the laureate or laureates in Physics give lectures in the Aula Magna at Stockholm University, usually on December 8.

I was there and listened to it. Dr. Kao was present, but unfortunately he had been diagnosed with Alzheimer’s disease in 2004, and it was his wife who gave the lecture. At the same time, my colleague Leif Stensland who introduced me to fiber optics in 1976, was there. He was then confined to a wheelchair and was being cared for by his wife. It felt like a moment of both joy and sorrow.

Next Blog

My next blog post is scheduled to be published on Tuesday, May 12, 2026. It’s about the introduction and breakthrough in fiber-optic connectors and ribbon fiber technology. I introduced it as the first one outside Japan. It later became a global standard.

As part of my R&D efforts, I identified Fiber to the Home (FTTH) as the next key area to develop which was still in its infancy at the time.

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