Free-electron laser experiments on Si-H vibrations in a-Si: H

We present results of ultrafast vibrational transient-transmission, transient-grating and photon-echo experiments, performed with the infrared light of a free-electron laser on Si-H stretching vibrations in hydrogenated amorphous silicon. The observations indicate that the nature of the dynamics of the local stretching mode is quite different from that of the same mode in a crystalline environment.