Steven G. Johnson

Steven G. Johnson is an Associate Professor of Applied Mathematics and Physics at the Massachusetts Institute of Technology (MIT), affiliated with the Research Laboratory of Electronics (RLE). He holds a B.S. in physics, mathematics, and computer science (1995) and a Ph.D. in physics (2001), both from MIT. His research spans the influence of complex geometries on wave phenomena, high-performance computation (including FFTW library development), and nanoscale electromagnetism in structured media.

Johnson's work focuses on two primary areas: photonic crystals and high-performance computing. He co-developed the FFTW fast-Fourier transform library, earning the 1999 J.H. Wilkinson Prize. His research group explores nanostructure effects on partial differential equations, numerical electromagnetism, and device design. He teaches courses such as Mathematical Methods in Nanophotonics and Numerical Methods, reflecting his expertise in computational physics.

Key contributions include advancing surface-enhanced Raman scattering substrates, inverse design of meta-optics, and quasi-normal mode theory. Collaborations span experimental and theoretical groups, including the Ab Initio Physics Group at MIT. His team's work bridges fundamental theory with applied photonics, yielding innovations in imaging, lasers, and computational tools.

Recent projects highlight end-to-end metasurface design for imaging, physics-enhanced machine learning models, and tunable terahertz lasers. Johnson's interdisciplinary approach integrates nanophotonics, optimization, and AI, driving advancements in light-matter interaction and computational methods.