The Journal of Systems Engineering and Electronics （English Edition） is a comprehensive academic periodical jointly sponsored by the Second Academy of China Aerospace Science and Industry Corporation, the Chinese So...The Journal of Systems Engineering and Electronics （English Edition） is a comprehensive academic periodical jointly sponsored by the Second Academy of China Aerospace Science and Industry Corporation, the Chinese Society of Astronautics, the Systems Engineering Society of China and the Chinese Association for System Simulation. It started publication in 1990, and now appears six times a year, distributed at home and abroad.展开更多
We discuss the dynamics of ultrashort pulsed laser excitation in bulk optical silica-based glasses(fused silica and borosilicate BK7) well-above the permanent modification threshold. We indicate subsequent structural ...We discuss the dynamics of ultrashort pulsed laser excitation in bulk optical silica-based glasses(fused silica and borosilicate BK7) well-above the permanent modification threshold. We indicate subsequent structural and thermomechanical energy relaxation paths that translate into positive and negative refractive index changes, compression and rarefaction zones. If fast electronic decay occurs at low excitation levels in fused silica via self-trapping of excitons,for carrier densities in the vicinity of the critical value at the incident wavelength, persistent long-living absorptive states indicate the achievement of low viscosity matter states manifesting pressure relaxation, rarefaction, void opening and compaction in the neighboring domains. An intermediate ps-long excited carrier dynamics is observed for BK7 in the range corresponding to structural expansion and rarefaction. The amount of excitation and the strength of the subsequent hydrodynamic evolution is critically dependent on the pulse time envelope, indicative of potential optimization schemes.展开更多
文摘The Journal of Systems Engineering and Electronics （English Edition） is a comprehensive academic periodical jointly sponsored by the Second Academy of China Aerospace Science and Industry Corporation, the Chinese Society of Astronautics, the Systems Engineering Society of China and the Chinese Association for System Simulation. It started publication in 1990, and now appears six times a year, distributed at home and abroad.
基金support of the Agence Nationale de la Recherche(projects ANR 2011 BS04010 NanoFlam and ANR 2011 BS09026 SmartLasir)
文摘We discuss the dynamics of ultrashort pulsed laser excitation in bulk optical silica-based glasses(fused silica and borosilicate BK7) well-above the permanent modification threshold. We indicate subsequent structural and thermomechanical energy relaxation paths that translate into positive and negative refractive index changes, compression and rarefaction zones. If fast electronic decay occurs at low excitation levels in fused silica via self-trapping of excitons,for carrier densities in the vicinity of the critical value at the incident wavelength, persistent long-living absorptive states indicate the achievement of low viscosity matter states manifesting pressure relaxation, rarefaction, void opening and compaction in the neighboring domains. An intermediate ps-long excited carrier dynamics is observed for BK7 in the range corresponding to structural expansion and rarefaction. The amount of excitation and the strength of the subsequent hydrodynamic evolution is critically dependent on the pulse time envelope, indicative of potential optimization schemes.
