Prof. Martina Hentschel from Chemnitz University of Technology will be speaking about


From billiards for light to mesoscopic optics

The investigation of the propagation of light in mesoscopic, often micrometer-scale systems is a rich subject providing insights ranging from quantum chaos in open systems to new schemes for microlasing devices. The concept of quantum-classical, here wave-ray, correspondence, proves to be a useful tool in many contexts. We illustrate the consequences of chaotic light dynamics and discuss its impact on the far-field emission characteristics of individual optical microcavities with and without internal sources as well as for arrays of coupled microcavities. For comparison, we also address electronic billiards with sources in single and bilayer graphene systems and confirm ray-wave correspondence to hold semi-quantitatively.

The propagation of electromagnetic waves in three-dimensional optical microcavities requires to pay attention to the light’s polarization evolution as a new degree of freedom. In systems like dielectric Möbius-strips or cone-shaped microtube cavities, the polarization state of resonant whispering gallery-type modes may differ strongly from the reference case of homogeneous cylinders. Whereas we find that the polarization of the electromagnetic field follows the wall orientation in thin Möbius strips, thereby reflecting the accumulated geometric phase, we observe that the electromagnetic field ignores the Möbius topology when the strip thickness is increased. In cylindrical three-dimensional optical systems, we observe spin-orbit interaction even for cylindrically symmetric cavities. The far-field emission possesses a characteristic polarization pattern that can be understood using vector diffraction theory and can be relevant for potential applications.

We will finish with an outlook on current and future research projects on systems with feedback, PT-symmetry, and other non-Hermitian systems.