Fraunhofer, Joseph von 1787-1826
German physicist

Born in Straubing, Bavaria, he went in 1806 to the optical workshop of the Munich Philosophical Instrument Company, where his skill in glass-making and scientific knowledge enabled him to transform the firm's fortunes, becoming a director of the company by 1811. In 1823 he was appointed director of the Physics Museum of the Bavarian Academy of Sciences. Fraunhofer advanced the design of achromatic doublet lenses, showing how to minimize their spherical aberration, and using these improved designs he developed the prism spectrometer to discover the dark lines in the Sun's spectrum which now bear his name (1814-17). He invented the transmission diffraction grating in 1821, and subsequently the reflection grating. Diffraction phenomena observed at very large distances from the diffracting aperture are known as Fraunhofer diffraction. His work laid the foundation for Germany's subsequent supremacy in the design and manufacture of optical instruments.