Resonant excitation of coherent phonons in CdTe/sub 1-x/Se/sub x/ quantum dots

Summary form only given. The mechanisms for the generation of coherent phonons with ultrafast laser pulses are not well understood for absorbing media. While the selection rules are usually consistent with those of stimulated Raman scattering, a definitive identification of the generation process hinges on analyses of the dependence of the phonon amplitude on the central frequency and width of the pulses. However, few resonant studies have been reported in the literature. We describe experiments on CdTe/sub 1-x/Se/sub x/ quantum dots revealing a large resonant enhancement in the coherent phonon yield at laser energies in the vicinity of the fundamental gap.