Dynamics of ultrafast reversible phase transitions in GeSb films triggered by picosecond laser pulses

Dynamics of Ultrafast Phase Changes in Amorphous GeSb Films

The existence of nonthermal, ultrafast phase transitions after strong femtosecond laser excitation has been demonstrated in several materials such as silicon [1–3], gallium arsenide [3–6], indium antimonide [7], and carbon [8]. It is accepted that such transitions are induced by a softening of the lattice structure due to the generation of a very high density electron-hole plasma, as first prop...

Ultrafast laser-induced phase transitions in amorphous GeSb films.

Time-resolved measurements of the spectral dielectric function reveal new information about ultrafast phase transitions induced by femtosecond laser pulses in Sb-rich amorphous GeSb films. The excitation generates a nonthermal phase within 200 fs. The dielectric function of this phase differs from that of the crystalline phase, contrary to previous suggestions of a disorder-to-order transition....

The influence of wavelength on phase transformations induced by picosecond and femtosecond laser pulses in GeSb thin films

Gouy phase shift of single-cycle picosecond acoustic pulses

Ultrafast laser pulses are used to generate single-cycle picosecond acoustic pulses in thin metal films on silicon. For small initial excitation spot sizes, propagation of the acoustic pulses across a 485-mm Si crystal leads to significant diffraction effects. The temporal reshaping of the acoustic wave form due to diffraction is investigated, and we demonstrate that the acoustic far field can ...

Existence of electronic excitation enhanced crystallization in GeSb amorphous thin films upon ultrashort laser pulse irradiation.

The study of the interaction of ultrashort laser pulses with solids has raised some important questions concerning the nature of the transformations occurring at the material surface in the presence of very strong levels of electronic excitation. The existence of electronic excitation induced phase transitions has been already demonstrated in several materials (Si [1], GaAs [2–4], graphite [5])...