20 September 2004 Transient absorption phenomena and related structural transformations in femtosecond laser-excited Si
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Proceedings Volume 5448, High-Power Laser Ablation V; (2004) https://doi.org/10.1117/12.563168
Event: High-Power Laser Ablation, 2004, Taos, New Mexico, United States
Abstract
Analysis of processes affecting transient optical absorption and photogeneration of electron-hole plasma in silicon pumped by an intense NIR or visible femtosecond laser pulse has been performed taking into account the most important electron-photon, electron-electron and electron-phonon interactions and, as a result, two main regimes of such laser-matter interaction have been revealed. The first regime is concerned with indirect interband optical absorption in Si, enhanced by a coherent shrinkage of its smallest indirect bandgap due to dynamic Franz-Keldysh effect (DFKE). The second regime takes place due to the critical renormalization of the Si direct bandgap along Λ-axis of its first Brillouin zone because of DFKE and the deformation potential electron-phonon interaction and occurs as intense direct single-photon excitation of electrons into one of the quadruplet of equivalent Λ-valleys in the lowest conduction band, which is split down due to the electron-phonon interaction.
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Sergey I. Kudryashov, "Transient absorption phenomena and related structural transformations in femtosecond laser-excited Si", Proc. SPIE 5448, High-Power Laser Ablation V, (20 September 2004); doi: 10.1117/12.563168; https://doi.org/10.1117/12.563168
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