Dephasing dynamics of coherent phonons in heavily doped Si under non-resonant photoexcitation

Ultrashort laser pulses allow us to do the real-time observation of carrier and phonon dynamics. Under the resonant excitation, the strong coupling between carriers and coherent phonons in Si is observed in time-domain. By using photon below the direct band gap (-3.4 eV), Si is excited non-resonantly from the valence band and the conduction band p- and n-type Si, respectively. An opposite effect between p- and n-type doping on the dephasing dynamics of coherent phonons is observed.