Open AccessTightly focused femtosecond laser pulse in air: from filamentation to breakdown
Author(s) -
Xiaolong Liu,
Xingqiang Lü,
Xun Liu,
Tingting Xi,
Liqiang Feng,
Jing Ma,
Jie Zhang
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.026007
Subject(s) - filamentation , femtosecond , optics , shadowgraph , laser , materials science , femtosecond pulse shaping , interferometry , pulse (music) , physics , detector
The propagation of tightly focused femtosecond laser pulse with numerical aperture of 0.12 in air is investigated experimentally. The formation and evolution of the filament bunch are recorded by time-resolved shadowgraph with laser energy from 2.4 mJ to 47 mJ. The distribution of electron density in breakdown area is retrieved using Nomarski interferometer. It is found that intensity clamping during filamentation effect still play a role even under strong external focusing. The electron density in some interaction zones is higher than 3 × 10(19) cm(-3), which indicates that each air molecule there is ionized.