Speaker
Dr
Alex Paarmann
(Fritz-Haber-Institut, Berlin, Germany)
Description
The immense spectral brightness of infrared free-electron lasers is ideally suited to resonantly drive large magnitude lattice vibrations in dielectric crystals. In particular for optical phonons, their many ps-long life times result in sharp spectral resonances in the mid- to far-infrared, perfectly matching the tuning range and narrow bandwidth of IR-FELs. In this talk, I will give several examples of nonlinear phonon spectroscopy demonstrating these capabilities: second harmonic phonon spectroscopy, two-photon absorption spectroscopy, and vibrational sum-frequency spectroscopy. Based on these examples, I will discuss the prospect of FEL-based nonlinear solid-state spectroscopy.
Primary author
Dr
Alex Paarmann
(Fritz-Haber-Institut, Berlin, Germany)
