Ultrafast far-infrared dynamics probed by terahertz pulses: a frequency domain approach. I. Model systems.
Time-resolved terahertz spectroscopy has become a widely used experimental tool for the investigation of ultrafast dynamics of polar systems in the far infrared. We have recently proposed an analytical method for the extraction of a transient two-dimensional susceptibility from the experimental data [Nĕmec, Kadlec, and Kuzel, J. Chem. Phys. 117, 8454 (2002)]. In the present paper the methodology of optical pump-terahertz probe experiments is further developed for direct application in realistic experimental situations. The expected two-dimensional transient response function is calculated for a number of model cases (including Drude dynamics of free carriers, harmonic and anharmonic oscillator modes); these results serve as a basis for the interpretation of experimental results. We discuss also the cases where only partial (one-dimensional) information about the system dynamics can be experimentally obtained.
Nĕmec
H
H
Institute of Physics, Academy of Sciences of the Czech Republic, and Center for Complex Molecular Systems and Biomolecules, Na Slovance 2, 182 21 Prague 8, Czech Republic.
Kadlec
F
F
Surendran
S
S
Kuzel
P
P
Jungwirth
P
P