Abstract-Coherent phonon spectroscopy of non-fully symmetric modes using resonant terahertz excitation

T. Huber^1,a), M. Ranke², A. Ferrer^1,3, L. Huber¹ and S. L. Johnson¹
http://scitation.aip.org/content/aip/journal/apl/107/9/10.1063/1.4930021
1 Institute for Quantum Electronics, Physics Department, ETH Zurich, CH-8093 Zurich, Switzerland
2 The Hamburg Centre for Ultrafast Imaging, Luruper Chaussee 149, D-22761 Hamburg, Germany
3 Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland
a) Electronic mail: tihuber@phys.ethz.ch
Appl. Phys. Lett. 107, 091107 (2015); http://dx.doi.org/10.1063/1.4930021

We use intense terahertz (THz) frequency electromagnetic pulses generated via optical rectification in an organic crystal to drive vibrational lattice modes in single crystal Tellurium. The coherent modes are detected by measuring the polarization changes of femtosecond laser pulses reflecting from the sample surface, resulting in a phase-resolved detection of the coherent lattice motion. We compare the data to a model of Lorentz oscillators driven by the near-single-cycle broadband THz pulse. The demonstrated technique of optically probed coherent phonon spectroscopy with THz frequency excitation could prove to be a viable alternative to other time-resolved spectroscopic methods like standard THz time domainspectroscopy.