Stefan Hell

Max Planck Institute for Multidisciplinary Sciences

At the Max Planck Institute for Multidisciplinary Sciences in Göttingen and the Max Planck Institute for Medical Research in Heidelberg, Stefan Hell directs research groups that have repeatedly redrawn what optical microscopes can resolve. Born in Arad, Romania, and trained at Heidelberg, Hell is the Romanian-German physicist best known for conceiving and demonstrating stimulated emission depletion, or STED, microscopy — the first concept to break Abbe's diffraction barrier in far-field optical microscopy and bring fluorescence imaging down to the nanometer scale. For decades it was believed that the resolution of a light microscope could never resolve features closer than about half the wavelength of light. Hell showed this limit could be circumvented by using a second, doughnut-shaped beam to switch off fluorescence everywhere except a tiny central spot, sharpening the effective focus far below the diffraction limit. The Royal Swedish Academy of Sciences cited exactly this achievement when it gave him a one-third share of the 2014 chemistry Nobel for super-resolved fluorescence microscopy. Never content with one breakthrough, Hell kept squeezing resolution downward, inventing MINFLUX nanoscopy — a scheme that pinpoints single molecules with near-molecular precision by fusing coordinate-targeted and coordinate-stochastic tricks into one instrument. His inventions are commercialized through partnerships with Leica Microsystems and through the companies Abberior and Abberior Instruments, which supply super-resolution microscopes and dyes used widely in cell biology, neuroscience, and pharmaceutical research.