The techniques of single and multiple-pulse impulsive stimulated Raman scattering (ISRS) are used to explore the dynamics of the lowest frequency A1 polariton mode in the ferroelectric crystal lithium tantalate. This time-domain technique which allows unambiguous characterization of the frequency and damping dispersion of the polariton reveals anomalously high damping rates for the A1 mode. The damping behavior is explained by a model that includes coupling of the polariton to a weakly Raman-active relaxational mode and to two E-symmetry modes.
- impulsive stimulated Raman scattering
- lithium tantalate
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics