Abstract
Materials irradiated with multiple femtosecond laser pulses in subablation conditions are observed to develop various types of self-assembled morphologies that range from nanoripples to periodic microgrooves and quasiperiodic microspikes. Here, we present a physical scenario that couples electrodynamics, describing surface plasmon excitation, with hydrodynamics, describing Marangoni convection and counter-rolls, to elucidate this important subablation regime of light-matter interaction in which matter is being modified; however, the underlying process is not yet fully understood. The proposed physical mechanism could be generally applicable to practically any conductive material structured by ultrashort laser pulses; therefore it can be useful for the interpretation of further critical aspects of light-matter interaction.
- Received 6 September 2014
- Revised 5 June 2015
DOI:https://doi.org/10.1103/PhysRevB.92.041405
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