Coherent LO phonon oscillations excited by 20-fs ultrashort laser pulses have been observed in isotopic 70Ge/74Ge superlattices by a pump-probe technique. Fourier-transformed spectra of the time-domain signal were compared with incoherent LO phonon spectra measured by Raman spectroscopy. The spectra of coherent phonons are quite different from the Raman spectra with common excitation wavelength. This comparison indicates that the pump-probe experiment detects the region which is different from where Raman experiment probes.
|ジャーナル||Journal of Luminescence|
|出版物ステータス||Published - 2000 5|
|イベント||International Conference on Luminescence and Optical Spectroscopy of Condensed Matter (ICL'99) - Osaka, Jpn|
継続期間: 1999 8 23 → 1999 8 27
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics