In Memoriam: Prof. Akira Hasegawa (1934-2025)

Dr. Akira Hasegawa, former adjunct professor at Columbia’s Department of Applied Physics and Applied Mathematics, peacefully passed away on June 22, 2025, with his beloved wife Miyoko by his side. Despite a diagnosis of myelodysplastic syndrome in June 2024 and a prognosis of just months, Akira defied expectations, celebrating his 91st birthday just days before he passed away.

Akira Hasegawa was born in Tokyo in 1934. He is a graduate of Osaka University and received his Ph. D. Degree from the University of California, Berkeley and, later, a Doctor of Science Degree from Nagoya University. After graduation, he was a post-doctoral scientist at Bell Laboratories and an associate professor in the Faculty of Engineering Science of Osaka University. In 1968, Hasegawa returned to Bell Laboratories where he made pioneering discoveries of plasma wave phenomena in the Earth's magnetosphere. While at Bell Labs, Hasegawa became an adjunct professor in 1971 Columbia University and was a source of inspiration and ideas to members of Columbia's plasma physics and fusion research program. In 1987 Hasegawa proposed confining a high-temperature plasma by a levitated superconducting dipole magnet. This invention lead to two successful demonstrations of high-pressure plasma confinement: at the Levitated Dipole Experiment (LDX) built jointly by Columbia University and MIT and at the "Ring Trap-1" device built at the University of Tokyo.

Professor Hasegawa is recognized for many discoveries in plasma physics and nonlinear optics. The American Physical Society awarded Hasegawa the 2000 James Clerk Maxewell Prize for “innovative discoveries and seminal contributions to the theories of nonlinear drift wave turbulence, Alfvén wave propagation in laboratory and space plasmas, and optical solitons and their application." In 2011, he was co-recipient of the 2011 Hans Alfvén Prize awarded by the European Physical Society "for laying the foundations of modern numerical transport simulations and key contributions on self-generated zonal flows and flow shear decorrelation mechanisms which form the basis of modern turbulence in plasmas.” In the field of nonlinear optics and communications, Hasegawa derived the master equation for information transfer in optical fibers and was the first to proposed the use of solitons for optical communications. In 1995, Hasegawa received the Computers and Communications Prize from the NEC Foundation "for the discovery of soliton in optical fiber and the pioneering contributions made in the applications for ultra high speed optical fiber communication" and later the 1999 Quantum Electronics Award from the IEEE Photonics Society. In 2010, the Emperor of Japan bestowed Akira Hasegawa The Order of the Sacred Treasure, Gold Rays with Neck Ribbon for his innovative discoveries and fundamental contributions in the field of physics.

His final year was filled with joy—time with friends and family, favorite meals, nature’s beauty, and deep gratitude for a life rich in purpose and love. He often reflected on how fortunate he was, thankful for the freedom to pursue his passion at Bell Labs and through his affiliations with several universities. Akira is survived by his wife, who lovingly cared for him until the end. He was also a father of three and a proud grandfather to five. Akira was surrounded by love in his final days. As he said, Shiawase datta — "I had a wonderful life."