Ernst Ruska

Ernst August Friedrich Ruska (December 25, 1906–May 27, 1988) was a German physicist.

Ruska was born in Heidelberg. He was educated at the Technical University of Munich from 1925 to 1927 and then entered the Technical University of Berlin, where he posited that microscopes using electrons, with waves 1,000 shorter than those of light, could provide a more detailed picture of an object than a microscope utilizing light, in which magnification is limited by the size of the wavelengths. In 1931, he built an electron lens and used several of these in a series to build the first electron microscope in 1933.

Ruska worked at Siemens-Reiniger-Werke AG as a research engineer from 1937 to 1955 and then served as director of the Institute for Electron Microscopy of the Fritz Haber Institute from 1955 to 1972. Concurrently, Ruska served at the institute and as professor at the Technical University of Berlin, from 1957 until his retirement in 1972. In 1986, he won half of the Nobel Prize in Physics for his many achievements in electron optics; Gerd Binnig and Heinrich Rohrer won a quarter each for their design of the scanning tunneling microscope. He died in West Berlin in 1988.