7. Networks
7.4. Jun-ichi Nishizawa

Figure 1: Jun-ichi Nishizawa.
Source: 日本学士院 / Wikimedia Commons (2022)
Downloadable teaching resource
Overview
Jun-ichi Nishizawa (西澤 潤一) was a prominent electrical engineer whose inventions have significantly contributed to internet technologies including fibre optics.
Background
Jun-ichi Nishizawa was born in 1926 in Sendai, Japan, and died there in 2018. Despite initial struggles to have his work accepted, he had an illustrious career as scientist, engineer, inventor, president of various universities and government advisor. Jun-ichi received his PhD degree in engineering from Tohoku University, where he became director of the Research Institute of Electrical Communication and later president of the university.
Contributions
His earlier work in microelectronics and semiconductor technology included the invention of the PIN diode and static induction technologies. Later inventions such as the avalanche photodiode and semiconductor optical maser were instrumental in the development of optical fibre communications (Siegel, 2015).
The following video from VIS Science (2023) gives an accessible introduction to Nishizawa's work.
Watch
Video 1: Jun-ichi Nishizawa: Revolutionizing Internet Technology (VIS Science, 2023)
Transcript
Jun-ichi Nishizawa is known for his electronic inventions since the 1950s and he is recognized for his contributions to the development of internet technology and the information age. He was a professor at Sofia University and he is considered the father of Japanese microelectronics.
His name is Jun-ichi Nishizawa. In the world of electronic engineering one name stands out as a true Pioneer, Jun-ichi Nishizawa, a remarkable Japanese engineer and inventor from the 1950s onwards. Nishizawa left an indelible mark on the field with his groundbreaking electronic inventions that would shape the future. One of his most notable contributions was the invention of the pin diode which revolutionized electronic communications and paved the way for the development of internet technology but Nishizawa didn't stop there- he went on to invent the static induction transistor in the static induction thyristor, pushing the boundaries of electronic engineering even further. These novel inventions played a crucial role in the advancement of Information Technology laying the foundation for the information age we know today.
A distinguished professor at Sofia University, Nishizawa earned the well-deserved title of the 'father of Japanese microelectronics'. His work and dedication to the field have left an enduring legacy that continues to shape the future of technology. Jun-ichi Nishizawa's genius and Innovative spirit will forever be remembered as he played a pivotal role in propelling electronic engineering into New Frontiers.
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Jun-ichi Nishizawa, a brilliant Japanese scientist, made groundbreaking discoveries in the field of electronics and communication. In 1950, together with Yasushi Watanabe, Nishizawa invented the static induction transistor, a crucial advancement in solid-state electronics. This transistor played a vital role in the miniaturization and efficiency of electronic devices. Not content with just one Innovation, Nishizawa and his colleagues also invented the pin photodiode in the same year. This photodiode revolutionized optical communication by allowing the detection of light signals with high sensitivity and accuracy. Building on his previous successes Nishazawa went on to invent the Avalanche photodiode in 1952. This invention greatly enhanced the detection of weak optical signals, making it an essential component in various communication systems. In 1955 Nishazawa made an extraordinary breakthrough by creating the world's first solid-state Mazer. This device generated coherent microwaves using solid-state materials, paving the way for the development of more powerful microwave technologies. Never wanting to rest on his laurels, Nishizawa proposed the concept of a semiconductor Optical Mazer in 1957, a year before [other scientists] published their paper on optical mazers. This idea laid the foundation for the development of semiconductor lasers revolutionizing optical communication.
Continuing his remarkable career Nishazawa suggested the use of fiber optics for communication in 1963 while working at Tohoku University. His proposal for fiber optic communication opened up new possibilities for transmitting information over long distances with minimal loss and interference. Nishazawa's contributions to optical fiber communications did not stop there- in 1964 he patented the graded index optical fiber which allowed for efficient transmission of light signals from semiconductor lasers. This Invention played a crucial role in the widespread adoption of fiber optic technology. In 1971 Nishazawa added another achievement to his already impressive list by inventing the static induction thyristor. This semiconductor device enabled precise control of electrical power making it essential in various industrial applications.
Through his relentless pursuit of knowledge and unwavering dedication to scientific advancement, Junichi Mishizawa forever changed the landscape of electronics and communication. His inventions continue to shape the way we live and communicate in the modern world. Do you want to explore more scientists? Who do you want to see featured next? Subscribe and leave a comment below to let me know. I'll see you in the next video (based on VIS Science, 2023)
Nishizawa was awarded the IEEE Edison Medal in 2000. The IEEE later established the "Jun-ichi Nishizawa Medal", in tribute to Nishizawa's wide ranging contributions in computing communications (Siegel, 2015).
Feature: Digital communications now
To learn more about how fibre optics features in modern networking visit the free 'Digital communications' course (OpenLearn, 2018).
The introductory section explains how optical fibres can transmit high data rates over long distances. They have therefore largely replaced older copper wires for "trunk network" communication between major exchanges, and are increasingly used for "last mile" communications from the final telephone exchange to homes or businesses (OpenLearn, 2018).
See also
Yasushi Watanabe: inventor and collaborator with Nishizawa (Itoh, 2025)
Narinder Kapany was an earlier innovator in fibre optics.
References and further reading
Itoh, T. (2025) Jun-ichi Nishizawa 1926-2018. Available at: https://www.nae.edu/280907/JUNICHI-NISHIZAWA-19262018 (Accessed 21 January 2025)
Nakamura, S. and Nishizawa, J. (2001) Discovery of Discovery Blue Red. Japan: Hakujitsu-sha:Broad Daylight Inc.
OpenLearn (2018) Digital communications. Available at: https://www.open.edu/openlearn/digital-computing/digital-communications (Accessed 23 February 2025)
Siegel, P. H. (2015) 'Terahertz Pioneer: Jun-ichi Nishizawa “THz Shogun', IEEE Transactions on Terahertz Science and Technology, 5(2), pp. 162-169. Available at: https://doi.org/10.1109/TTHZ.2015.2399699 (Accessed 22 January 2025)
VIS Science (2023) Jun-ichi Nishizawa: Revolutionizing Internet Technology | Jun-ichi Nishizawa Biography | Scientist. 4 August. Available at: https://www.youtube.com/watch?v=_6IFGxEWAYk (Accessed: 22 January 2025)
日本学士院 (2022) File:Junichi Nishizawa.jpg. Available at: https://commons.wikimedia.org/wiki/File:Junichi_Nishizawa.jpg (Accessed 09 February 2025)
