Nonlinear space-time focusing and filamentation of annular femtosecond pulses in dielectrics
نویسندگان
چکیده
Filamentation during simultaneous space-time focusing in bulk fused silica is investigated numerically. We model the use of a pair of concentric gratings to transform a common femtosecond laser pulse with Gaussian spatial profile into a radially chirped, annular beam shape that is focused into the bulk of silica by a lens. By varying the energy and/or time-chirp of the incident pulse, we capture the pulse dynamics and material response that yields material modification and damage in the nonlinear focus. The results show rich pulse dynamics, enhanceddamage/modification site localization, and suggest novel approaches to laser machining of solids. © 2016 Optical Society of America
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