Lattice Dynamics
Research Group Alexander Paarmann
Lattice Dynamics
Research Group Alexander Paarmann


Welcome to the Lattice Dynamics group website!

Our group is interested in optical phonons in polar dielectric crystals and their heterostructures. We use various linear and nonlinear mid-infrared to THz spectroscopy techniques, employing the Infrared Free Electron Laser (IR-FEL) at the FHI as an intense and tunable light source.

Using this unique laser, we study various problems ranging from infrared nanophotonics to phase transitions in complex oxides. Check out our research page and our recent publications for more information!

New group member - Richarda
Nov 2019
Richarda just joined the team to work on sum-frequency generation microscopy. Welcome!
Transfer matrix finally goes birefringent
Nov 2019
After we struggled with a problem in our 2017 transfer matrix paper for quite a while, we finally managed to solve the problem and just published the erratum. We also updated the matlab code and now, thanks to Mathieu, also have a Python implementation. This was a piece of work. Yay, Nikolai! We are glad to see that people are interested!
SFG microscopy paper published
Oct 2019
Riko‘s paper on the first demonstration of long-wave infrared SFG microscopy has just appeared in ACS Photonics! Congrats, Riko!
GST work published in Adv. Opt. Mat.
Sep 2019
Nikolai‘s work one switchable polaritons and polariton-like waveguide modes in GST/SiC just got published in Adv. Opt. Mat., to be part of a special issue on “Polaritons in Nanomaterials”. Thanks again to Thomas Taubner for this collaboration. The work is also highlighted here.
Switchable polariton-like waveguide modes
Jun 2019
Nikolai just submitted a paper (arXiv link) demonstrating s-polarized waveguide modes in thin films of a phase-change material on a polar dielectric substrate. These modes have very similar properties to “classical” surface phonon polaritons, thus opening up new opportunities for omnipolarized nanophotonics. Thanks to Thomas Taubner for this very productive collaboration. Cool stuff!