Replica of the first gas laser in Germany from 1962.

The oldest discipline in physics

Milestones in nonlinear optics​
Replica of the first gas laser in Germany from 1962.
Image: Jan-Peter Kasper (University of Jena)

Milestones in nonlinear optics

Die Wurzeln der Optik reichen bis weit in die Antike.
The roots of optics
The roots of optics, the oldest discipline in physics, can be traced back to the ancient world, where philosophers such as Pythagoras, Ptolemy and Plato advocated the theory of ›rays of vision‹, whereby light was thought to originate in the eye itself and—similar to a lighthouse beam—scan the outside world. The mathematician Euclid (3rd c. BC) described these ›rays of vision‹ as emanating linearly from the eye and being reflected by the outside world.

Milestones in nonlinear optics in Jena

Die ersten Glaslaser werden in Jena gebaut.
Die ersten Glaslaser werden in Jena gebaut.
Image: Liana Franke/Universität Jena

Reinhart Neubert (*1935) built the first gas laser in Germany—in Jena—in 1962. Exactly 50 years later, the University of Jena awarded the laser pioneer an honorary doctorate.

Den ersten Lehrstuhl für nichtlineare Optik gibt es in Jena.
Den ersten Lehrstuhl für nichtlineare Optik gibt es in Jena.
Image: Liana Franke/Universität Jena

The first chair of nonlinear optics in Germany was held by Max Schubert (1926–1998), who was appointed to the University of Jena in 1964. Together with his student, the physicist Bernd Wilhelmi (1938–2018), Schubert wrote an ›Introduction to Nonlinear Optics‹, a textbook that subsequently became an international standard work.

Der Physiker Gerhard Paulus entdeckt Hohe Harmonische bei Photoionisation.
Der Physiker Gerhard Paulus entdeckt Hohe Harmonische bei Photoionisation.
Image: Liana Franke/Universität Jena

Six years after Anne L’Huillier had discovered high harmonics, Gerhard Paulus (*1966), who was appointed to the University of Jena in 2007, demonstrated the corresponding effect in photoionization. In 2015, Anne L’Huillier became the first female honorary doctor of the Faculty of Physics and Astronomy at the University of Jena.

Der vorläufige Schlusspunkt der nichtlinearen Optik ist die relativistische Laserphysik.
Der vorläufige Schlusspunkt der nichtlinearen Optik ist die relativistische Laserphysik.
Image: Liana Franke/Universität Jena

As it stands, the most advanced school of thought in nonlinear optics is the field of relativistic laser physics. When the laser fields are so strong that the electrons are accelerated to almost the speed of light, a whole new class of characteristic effects is produced. The first chair in this field is currently held by Malte Kaluza (*1974) at the University of Jena.