Akira Hasegawa
Akira Hasegawa is a Japanese theoretical physicist and engineer who has worked in the U.S. and Japan. He is known for his work in the derivation of the Hasegawa–Mima equation, which describes fundamental plasma turbulence and the consequent generation of zonal flow that controls plasma diffusion. Hasegawa also made the discovery of optical solitons in glass fibers, a concept that is essential for high speed optical communications.
Hasegawa was the first to suggest the existence of optical solitons in 1973. In 1974, he showed that plasmas could be heated with the kinetic Alfvén wave. Hasegawa and Chen introduced the concept of the kinetic Alfven wave to illustrate the microscopic process of the Alfven wave heating. In 1977, Hasegawa introduced the Hasegawa–Mima equation to describe turbulence in Tokamak plasmas and then further developed it in the 1980s to obtain the Hasegawa-Wakatani equation. The equation predicted an inverse cascade in the turbulent energy spectrum and zonal flows that can control radial turbulent diffusion. With Wakatani, he wrote a paper on self-organized turbulence in plasmas.
Hasegawa was the first to suggest the existence of optical solitons in 1973. In 1974, he showed that plasmas could be heated with the kinetic Alfvén wave. Hasegawa and Chen introduced the concept of the kinetic Alfven wave to illustrate the microscopic process of the Alfven wave heating. In 1977, Hasegawa introduced the Hasegawa–Mima equation to describe turbulence in Tokamak plasmas and then further developed it in the 1980s to obtain the Hasegawa-Wakatani equation. The equation predicted an inverse cascade in the turbulent energy spectrum and zonal flows that can control radial turbulent diffusion. With Wakatani, he wrote a paper on self-organized turbulence in plasmas.
