Joseph J.M. Braat (born 5 November 1946) is a Dutch optical engineer. Between 1973 and 1998 he worked in the Philips Research Laboratories. He subsequently was professor of optics at Delft University of Technology between 1998 and 2008.
Braat was born in Breda on 5 November 1946. He studied physics at Delft University of Technology and his thesis was focused on holography using spatially incoherent light. He subsequently moved to France and worked at the coherent optics group of the Institut d'Optique under Serge Lowenthal. In 1973 Braat returned to the Netherlands and started working at the Philips Research Laboratories. There he focused his research on optical disc systems. During this period he developed a theory together with Hopkins and Bouwhuis on the reading of optical discs.
In 1988 Braat became a part-time professor of geometrical optics at Delft University of Technology. In 1998 he became a full professor of optics. During this time he performed research on extreme ultraviolet lithography, optical aperture synthesis, high density optical recording and Terahertz imaging. Braat retired in 2008.
In 1991 Braat was one of the founders of the European Optical Society. From 2004 to 2006 he served as its President. In 1994 Braat won the Edward Longstreth Medal of the Franklin Institute. Braat was elected a member of the Royal Netherlands Academy of Arts and Sciences in 2001.
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- Karen Mauve (19 June 1998). "Joseph Braat: verlaat het lab" (PDF) (in Dutch). Hagenbeuk.nl. Archived from the original (PDF) on 7 January 2018.
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