Single and multiple-pulse impulsive stimulated Raman-scattering (ISRS) experiments are used to investigate the anomalously high damping rates of the lowest frequency A1 polariton in LiTaO3. The wave-vector dependence of the response reveals coupling of the polariton to a weakly Raman-active, low-frequency relaxational mode as well as to two underdamped modes of a different symmetry. Inclusion of the coupled modes yields quantitative agreement between the results and the predictions of a previously developed theory for light scattering from polaritons.
ASJC Scopus subject areas
- Condensed Matter Physics