Ultrafast Laser-Induced Elastodynamics in Single Crystalline Silicon Part II: Near-Field Response

• Published in: Journal of thermal stresses Vol. 32; no. 5; pp. 494 - 511
• Main Authors: Qi, Xuele, Suh, C. Steve
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01.05.2009
• Subjects: Axisymmetric model; Multi-time scale; Near-field response; Silicon wafer; Staggered finite difference scheme; Ultrafast laser pulse
• ISSN: 0149-5739; 1521-074X
• DOI: 10.1080/01495730802637399

The multi-time scale ultrafast laser model of axisymmetric geometry presented in Part I is validated with computed carrier densities and melting thresholds that agree well with published physical data. Transport phenomena initiated by femtoseconds heating including the spatial and temporal evolutions of electron and lattice temperatures and electron-hole carrier density are highly localized in both time and space. The temporal and spatial scales associated with the generation of thermal stress waves are significantly larger at tenths of nanoseconds and microns, respectively. Ultrashort laser pulse induced transverse stress waves are highly dispersive and characteristically of broadband, low amplitude, and extremely high frequency and power density contents. Near-field responses that precede the development of a full-blown plate wave are also localized in space with a power density magnitude on the order of 10 13 Watts per cubic meters in volume.