The history of the Optics Research Group since 1947.


Prof. dr. A.C.S. van Heel (1899-1966)

Founder of the Optics Group

  • 1918 – 1925: Physics study in Leiden; concluded with a dissertation, “The solid body optically examined at low temperatures”, supervisor H. Kamerlingh Onnes.
  • 1924 – 1928: (chief) assistant TH Delft (General Sciences).
  • Research Topics: Alignment techniques, Optical design, Optical manufacturing, Thin optical layers.
  • 1939: Founding of the N.V. van Leers Optical Industry later known as the “De Oude Delft” together with Oscar van Leer.
  • 1941: Establishment of the Technical-Physical Service, TNO-TH (Dorgelo initiative).
  • 1947: Appointed professor of the Optics group.


Prof. dr. H. de Lang

  • 1967 – 1969
  • Background: Philips Research.
  • Research topics: Thin layer optics, optical metrology, anisotropic media and optical cavities.


Dr. ir. C.A.J. Simons (1937 – 2009)

  • Transitional period (1969 – 1970)
  • Dissertation: “The application of individual functions in the practice of optical design”, supervisor Prof. H. de Lang (1969).

Dr. ir. W. van Vonno (1941)

  • Thesis: “Measurement of the thickness and refractive index of evaporated thin films, supervisor Prof. H. de Lang (1968).


Prof. dr. ir. H.J. Frankena

  • Background: electromagnetism.
  • Thesis: “Scattering of electromagnetic waves by a class of waveguide discontinuities”, supervisor prof. A.T. de Hoop (1967).
  • Research topics: Optical manufacturing, Integrated Optics, Holography and Metrology.
  • 1998: Emeritaat.


Prof. dr. ir. Joseph J.M. Braat

  • 1988: Part-time professor in geometrical optics at Delft University of Technology.
  • 1998: Professor of the Optics Research Group.
  • Research topics: Extreme ultraviolet lithography, optical aperture synthesis, high density optical recording and Terahertz imaging. Joseph Braat retired in 2008.
  • 1991: Joseph Braat is one of the founders of the European Optical Society (EOS).
  • 2008: Emeritaat
  • 2019: Joseph Braat, and co-author Peter Török published the book “Imaging Optics”.


Prof. dr. H. Paul Urbach

Present leader of the Optics Research Group

  • In 1986 Paul Urbach completed his PhD thesis at the University of Groningen in the Netherlands on the optimization of hydrodynamic propulsion.
  • In 1986, he joined Philips Research Laboratory in Eindhoven, the Netherlands.
  • 2000: Part-time professor in diffraction optics at Delft University of Technology.