Zoek in de site...

Seminar by prof. Alexander Paarmann (Fritz-Haber institute, Berlin, Germany) (Lecture)

Monday 26 June 2017Add to my calendar
from 16:00
prof. Alexander Paarmann (Fritz-Haber-Institute, Berlin, Germany)

AlexPaarmannThere has been much increasing interest recently in the mid-infrared spectral response of polar dielectric crystals due to a novel branch of photonics based on surface phonon polaritons (SPhPs) [1]. These excitations arise at the surfaces and interfaces of these materials due to the optical phonon resonances in the dielectric response. Using our in-house free-electron laser [2] as intense and tunable infrared light source, we have developed several new approaches of nonlinear solid state spectroscopy, focusing on phonon resonances in dielectrics. The majority of the talk will discuss mid-IR second harmonic generation (SHG) spectroscopy, exemplified with a model study of SiC [3], and used to study hybdrid optical phonons in atomic-scale heterostructures [4]. We also apply the technique to probe the field enhancement associated with resonantly excited SPhPs in sub-diffractional nanostructures [5], as well as prism-coupled propagating SPhPs [6]. Finally, I will also report on our recent implementation of a synchronized optical laser, which we apply to study to timing jitter characteristics and macropulse-resolved micropulse shape of the FEL pulses, using a balanced optical cross-correlator.

[1] Caldwell, et al. Nanophotonics 4, 1 (2015) [2] Schöllkopf et al., Proc. SPIE 9512, 95121L (2015) [3] Paarmann, et al. Appl. Phys. Lett. 107, 081101 (2015) [4] Caldwell, et al., Nature Nanotechnology 11, 9 (2016) [5] Razdolski, et al., Nano Letters Nano Letters 16, 6954 (2016) [6] Passler, et al., ACS Photonics 4, 1048 (2017)

prof. Andrei Kirilyuk