The generation of coherent optical oscillations in 150 οm thick bulk GaN was reported. At photon energy below the bandgap, the generation mechanism of coherent phonon modes was revealed to be impulsive stimulated Raman scattering. One among the two degenerate E2 modes was selectively detected with a proper choice of probe polarization. Dephasing times ranged from 1.5 to 70 ps for different modes, and phonon-three-photon absorbed carrier interactions were compared between the modes.
|Number of pages||4|
|Journal||Physical Review Letters|
|State||Published - 2002 Mar 11|