Nonlinear propagation of tailored caustics

At the ‚nonlinear photonics‘ group, we create innovative concepts in order to tailor and control the propagation of light. Therefore, we especially benefit from nonlinear effects that allow for a strong light-matter interaction. This active field of research is a part of a broad worldwide community to which we contribute in particular by investigating photonic systems on basis of photorefractive materials.

An important field of this more general subject is the investigation of properties and possibilities of so-called photonic lattices. The fundamental concept of these structures is to spatially modulate the refractive index of a photosensitive material and thus to control propagation effects of light.

This thesis’ subject is about the realization of caustics in spatially tailored light fields, and their application to optically induce photonic structures in photorefractive crystals. Caustics thereby manifest as geometrical structures that represent singularities in the intensity, as predicted by catastrophe theory. The corresponding beams, e.g. the Airy, Pearcey, and further higher-order caustic beams, show unique features, like the propagation of the light field on curved trajectories in vacuum. Thus, these beams are highly suited to inscribe curved waveguides or rather complex structures in crystals. This thesis provides versatile possibilities for investigations – we work in experiment, simulate the light field’s propagation numerically and calculate theoretically the geometric structure of the caustics.

We are looking for active students, that are interested in optics and photonics, whose desire it is to contribute to actual research.

Contact: If you are interested, please contact Alessandro Zannotti. We are pleased if we may show you our laboratories and would like to present the offered topics in the subject of photonic structures in detail.