astronomy

Masataka Nakazawa

Masataka Nakazawa is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Masataka Nakazawa rather than just read about it. In short: Masataka Nakazawa (born 17 September 1952) is a Japanese researcher in optical communication engineering. He is a distinguished professor at Tohoku University in Japan.

Key takeaways

Masataka Nakazawa belongs to astronomy; place it in that map before memorising details.
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Connect Masataka Nakazawa to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Masataka Nakazawa from memory before moving on to harder problems.

Reference excerpt

Masataka Nakazawa (born 17 September 1952) is a Japanese researcher in optical communication engineering. He is a distinguished professor at Tohoku University in Japan. His pioneering work on erbium-doped fiber amplifier (EDFA) has made a significant contribution to the development of global long-distance, high-capacity optical fiber network.

Biography Masataka Nakazawa received B.S. in Electronics from Kanazawa University in 1975, M.S. in Physical Electronics from Tokyo Institute of Technology in 1977, and Ph.D. in Applied Electronics from Tokyo Institute of Technology in 1980. After receiving a Ph. D. degree, he joined the Electrical Communication Laboratory of Nippon Telegraph & Telephone Public Corporation in 1980. He was a visiting scientist at Massachusetts Institute of Technology in 1984. In 1999, he became an NTT R&D Fellow. Then, in 2001, he moved to the Research Institute of Electrical Communication (RIEC) at Tohoku University. He became a distinguished professor (DP) in 2008 and the director of RIEC in 2010. He also served as the director of Japan Council for Research Institutes and Centers of National Universities and of Research Organization of Electrical Communication (ROEC) in 2011. Currently, he is a director of Kanazawa University (part time) and a specially appointed professor/ distinguished professor at the International Research Institute of Disaster Science at Tohoku University

Research He introduced erbium ions into optical communication in 1984, when he constructed the first erbium (Er3+): glass laser operating at 1.55 μm, and then used it as an optical time domain reflectometer (OTDR). This enabled a fault to be located in a 130 km-long single-mode fiber, which remains the world record distance. He then began research on an erbium-doped fiber laser in 1987 and amplifier in 1989. After Dr. R. J. Mears of Prof. Payne’s group reported the first EDFA in 1987, Dr. Nakazawa used a 1.48 μm InGaAsP laser diode (LD) to pump the erbium fiber and reported the highest gain of 46.5 dB in 1989 after employing the LD for Raman amplification at 1.55 μm in 1988. He invented the LD pumped erbium-doped fiber amplifier (EDFA), which made it possible to construct a compact, reliable, and low-power consumption optical repeater for high-speed, high-capacity, and long-distance optical communication systems. He also reported backward Raman amplification in 1984, which remains in commercial use. He subsequently undertook intensive work on high-speed optical transmission technology using ultrashort Gaussian pulses, optical solitons, optical Fourier transformation, and Nyquist pulses. Nakazawa’s work spans diverse areas of photonics including optical communication, various fiber lasers, and quadrature amplitude modulation (QAM) coherent transmission with the highest multiplicity of 4096. Recently, he has been concentrating on Mode locking technology for the generation of various optical pulses and a QAM quantum noise stream cipher with continuous variable quantum key distribution (QKD). He has published more than 500 academic journal papers and given 400 international conference presentations. During his 40-year career he has received 5 paper awards and three centennial milestone certificates of commendation from the Institute of Electronics, Information, and Communication Engineers (IEICE).

Professional society membership He is a Fellow and Honorary Member of the Institute of Electronics, Information, and Communication Engineers (IEICE), a Fellow of the Japan Society of Applied Physics (JSAP), a Life Fellow of IEEE, and a Fellow Emeritus, OPTICA (formerly OSA). He also served as a Director at Large of the Optical Society of America (OSA) in 2007, on the Board of Governors of the IEEE Photonics Society in 2013, and as the President of IEICE in 2019

Awards and honors 1989 - Sakurai Kenjiro Memorial Award 1992 - OSA Fellow 1994 - IEICE Achievement Award 1995 - IEEE Fellow 2002 - IEEE Daniel E. Noble Award 2002 - Inoue Harushige Award from Japan Science and Technology Agency 2003 - Ichimura Industrial Award from Research Development Corporation of Japan 2005 - OSA Robert W. Wood Prize 2006 - Thomson Reuters Citation Laureates 2009 - Japan’s Prime Minister’s Award for Industry-Academia-Government Collaboration Meritorious Achievement 2010 - IEEE Quantum Electronics Award 2013 - Japan Academy Prize 2013 - C&C Prize 2014 - OSA Charles H. Townes Award 2023 - Japan Prize 2024 - Asian Scientist 100, Asian Scientist

References

Worked examples

Example 1 — a first encounter with Masataka Nakazawa

Start with the simplest possible case. Write down what Masataka Nakazawa claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Masataka Nakazawa before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Masataka Nakazawa ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Masataka Nakazawa

In research: Masataka Nakazawa appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Masataka Nakazawa in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Masataka Nakazawa is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1952 births, Academic staff of Kanazawa University, Academic staff of Tohoku University, so understanding it makes those chapters shorter.
In everyday life: Look for Masataka Nakazawa outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Masataka Nakazawa in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Masataka Nakazawa means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Masataka Nakazawa out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Masataka Nakazawa in simple terms?

Masataka Nakazawa (born 17 September 1952) is a Japanese researcher in optical communication engineering. He is a distinguished professor at Tohoku University in Japan.

Why does Masataka Nakazawa matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Masataka Nakazawa?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Masataka Nakazawa.