Displacive Excitation of Coherent Phonons
Abstract
Recently, we have shown that coherent lattice vibrations can be induced and subsequently detected in certain semimetals and semiconductors (e.g. Bi, Sb, Te, Ti2O3) via time-resolved optical pump-probe measurements using a CPM oscillator. The experimental data show in each case that only totally symmetric lattice modes (i.e., A1 symmetry) are coherently excited, even though other symmetry modes of comparable Raman cross-section exist. Furthermore, careful measurement of the coherent phonon phase reveals that the excitation mechanism for coherent phonons in these materials appears to be qualitatively different from that responsible for impulsive stimulated Raman scattering previously seen in organic dyes and crystals.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1993
- Accession Number
- ADA271727
Entities
People
- E. P. Ippen
- G. Dresselhaus
- H. J. Zeiger
- J. Vidal
- T. K. Cheng
Organizations
- Massachusetts Institute of Technology