Characteristics of femtosecond laser induced plasma filament in silica glass

抄録

Plasma filament can be induced by the interaction between femtosecond laser pulses and transparent dielectrics. It has received much attention because of its potential in micro processing fields. However, the evolution of filament in silica glass from femtosecond to nanosecond has not been well investigated. In this study, the spatiotemporal evolution of filaments induced by a femtosecond laser pulse in silica glass was observed using a time-resolved imaging method. The results indicated that the plasma relaxation was in approximately 0.8 ps, but the filament existed at least 971 ps after the plasma disappeared. This phenomenon can be attributed to the self-trapped excitons. Furthermore, the dependence of filament evolution on pump energies was investigated, and the filament length was quantitatively analyzed. This study contributes to the precise applications of femtosecond laser filamentation.