Ultrafast zone-center coherent lattice dynamics in ferroelectric lithium tantalate

摘要

Femtosecond time-resolved pump–probe experiments were carried out to study ultrafast lattice dynamics of ferroelectric lithium tantalate. Both the fully symmetric (A₁ mode) and doubly degenerate (E mode) coherent phonons at the center of the Brillouin zone were excited via impulsive stimulated Raman scattering, as confirmed by the excitation intensity dependence.