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Short-pulse laser induced transient structure formation and ablation studied with time-resolved coherent XUV-scattering

  • XUV- and X-ray free-electron-lasers (FEL) combine short wavelength, ultrashort pulse duration, spatial coherence and high intensity. This unique combination of properties opens up new possibilities to study the dynamics of non-reversible phenomena with ultrafast temporal and nano- to atomic-scale spatial resolution. In this contribution we wish to present results of time-resolved experiments performed at the XUV-FEL FLASH (HASYLAB/Hamburg) aimed to investigate the nano-scale structural dynamics of laser-irradiated materials. Thin films and fabricated nano-structures, deposited on Si3N4-membranes, have been excited with ultrashort optical laser pulses. The dynamics of the non-reversible structural evolution of the irradiated samples during laser-induced melting and ablation has been studied in an optical pump - XUV-probe configuration by means of single-shot coherent scattering techniques (i.e. diffraction imaging [1]). In a first set of experiments we investigated the formation ofXUV- and X-ray free-electron-lasers (FEL) combine short wavelength, ultrashort pulse duration, spatial coherence and high intensity. This unique combination of properties opens up new possibilities to study the dynamics of non-reversible phenomena with ultrafast temporal and nano- to atomic-scale spatial resolution. In this contribution we wish to present results of time-resolved experiments performed at the XUV-FEL FLASH (HASYLAB/Hamburg) aimed to investigate the nano-scale structural dynamics of laser-irradiated materials. Thin films and fabricated nano-structures, deposited on Si3N4-membranes, have been excited with ultrashort optical laser pulses. The dynamics of the non-reversible structural evolution of the irradiated samples during laser-induced melting and ablation has been studied in an optical pump - XUV-probe configuration by means of single-shot coherent scattering techniques (i.e. diffraction imaging [1]). In a first set of experiments we investigated the formation of laser induced periodic surface structures (LIPSS) on the surface of thin Si-films (thickness 100 nm). In a simplified view LIPPS are generated as a result of interference between the incident laser pulse and surface scattered waves which leads to a periodically modulated energy deposition. Time-resolved scattering using femtosecond XUV-pulses (with a wavelength of 13.5 nm and 7 nm) allowed us to directly follow LIPSS evolution on an ultrafast time-scale and with better than 40 nm spatial resolution. The observed scattering patterns show almost quantitative agreement with theoretical predictions [2] and reveal that the LIPSS start to form already during the 12 ps pump pulse. In the second set of measurements we studied picosecond and femtosecond laser induced ablation and disintegration of fabricated nano-structures. Correlations of coherent diffraction patterns measured at various time delays to the pattern of the undisturbed object show that order in the structure is progressively lost starting from short length scales. This structural rearrangement progresses at close to the speed of sound in the material. Under certain circumstances (e.g. adequate sampling) it became also possible to reconstruct real-space images of the object as it evolves over time [3]. The possibility of femtosecond single-shot imaging of ultrafast dynamic processes with nanoscale resolution provides yet more details of the physical processes involved. [1] H. N. Chapman et al. Nature Phys. 2, 839 (2006). [2] J. F. Young et al., Phys. Rev. B 27, 1155 (1983). [3] A. Barty et al. Nature Phot. 2, 415 (2008).zeige mehrzeige weniger

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Metadaten
Autoren/innen:K. Sokolowski-Tinten, A. Barty, S. Boutet, U. Shymanovich, M. Bogan, S. Marchesini, S. Hau-Riege, N. Stojanovic, Jörn Bonse, R. Tobey, H. Ehrke, A. Cavalleri, S. Duesterer, M. Frank, S. Bajt, J. Schulz, M. Seibert, J. Hajdu, R. Treusch, H. Chapman
Dokumenttyp:Beitrag zu einem Tagungsband
Veröffentlichungsform:Graue Literatur
Sprache:Englisch
Titel des übergeordneten Werkes (Englisch):Fall meeting of the materials research society 2009 - Symposium MM / Materials research society symposium proceedings
Jahr der Erstveröffentlichung:2010
Herausgeber (Institution):Materials Research Society
Jahrgang/Band:1230E
Ausgabe/Heft:Paper 1230-MM05-03
Erste Seite:1
Letzte Seite:6
Freie Schlagwörter:Femtosecond laser ablation; Laser-induced periodic surface structures; Semiconductor; Silicon; Time-resolved coherent XUV scattering
Veranstaltung:Fall meeting of the materials research society 2009
Veranstaltungsort:Boston, MA, USA
Beginndatum der Veranstaltung:2009-11-30
Enddatum der Veranstaltung:2009-12-04
DOI:https://doi.org/10.1557/PROC-1230-MM05-03
Bemerkung:
Serientitel: Materials Research Society symposium proceedings – Series title: Materials Research Society symposium proceedings
Verfügbarkeit des Volltexts:Papiergebundenes Belegexemplar in der Bibliothek der BAM vorhanden ("Hard-copy Access")
Bibliotheksstandort:Sonderstandort: Publica-Schrank
Datum der Freischaltung:19.02.2016
Referierte Publikation:Nein