HYBRID: Infrared Nanophotonics with Phonon Polaritons

This lecture will be held in presence in the Anna-von-Helmholtz-Bau of the Physikalisch-Technische Bundesanstalt in Berlin-Charlottenburg and can be followed online at the same time. Please use the links above to register your personal participation or to receive the access data for online participation.

Topic:

Phonon polaritons are mixed light-matter quasiparticles that enable extreme confinement of long-wavelength infrared and terahertz light to the nanoscale. The ability to tailor this light-matter interaction using 2D materials and artificially structured metasurfaces has made phonon polaritons a rapidly growing research field over the past decade. In my talk, I will introduce hyperbolic polaritons, which exhibit record-high confinement factors of x250 and peculiar ray-like propagation. Additionally, I will show how nonlinear sum-frequency microscopy enables imaging of polaritons trapped within metasurfaces.

CV:

Niclas Mueller grew up in Kassel, where he became interested in physics through Jugend forscht projects at a student research centre. After completing a voluntary year as an English teacher in China, he moved to Berlin to study physics at Freie Universität Berlin. There, he specialized in nano-optics and obtained his PhD in 2020. During the COVID pandemic, he relocated to the UK for a two-year research stay at the University of Cambridge. This was followed by postdoctoral research at the Fritz Haber Institute in Berlin. Since May 2025, Niclas has been establishing his own junior research group at Freie Universität Berlin, funded through the Emmy Noether Programme.

Following the lecture, there will be a get-together where participants can exchange ideas with each other over pizza and drinks.

The event is sponsored by the Wilhelm and Else Heraeus Foundation.