Spatial evolution of multiple filaments in air induced by femtosecond laser pulses.
نویسندگان
چکیده
The spatial evolution of plasma filaments in air induced by femtosecond laser pulses is investigated experimentally. Several major filaments and small scaled additional filaments are detected in the plasma channel. The complicated interaction process of filaments as splitting, fusion and spreading is observed. The major filaments propagate stably, and the small scaled additional filaments can be attracted to the major filaments and merged with them. The major filaments are formed due to the perturbation of initial beam profile and the small scaled filaments are mainly caused by the transverse modulational instability.
منابع مشابه
Optimization of multiple filamentation of femtosecond laser pulses in air using a pinhole.
The robustness and prolongation of multiple filamentation (MF) for femtosecond laser propagation in air are investigated experimentally and numerically. It is shown that the number, pattern, propagation distance, and spatial stability of MF can be controlled by a variable-aperture on-axis pinhole. The random MF pattern can be optimized to a deterministic pattern. In our numerical simulations, w...
متن کاملTerahertz radiation source in air based on bifilamentation of femtosecond laser pulses.
A new terahertz (THz) source in air based on the bifilamentation of femtosecond laser pulses is reported. This THz radiation is 1 order of magnitude more intense than the transition-Cherenkov THz emission from femtosecond laser filaments reported recently and shows different angular and polarization properties. We attribute it to the emission from a bimodal transmission line created by two plas...
متن کاملMultiple filamentation of terawatt laser pulses in air.
The filamentation of femtosecond light pulses in air is numerically and experimentally investigated for beam powers reaching several TW. Beam propagation is shown to be driven by the interplay between intense, robust spikes created by the defects of the input beam and random nucleation of light cells. Evolution of the filament patterns can be qualitatively reproduced by an averaged-in-time (2D+...
متن کاملOptical breakdown of air triggered by femtosecond laser filaments
Experiments on gas breakdown by powerful optical pulses date back to the early days of lasers. The following development resulted in the generation of dense plasma columns up to several tens of meters in length. Pulsed neodymium-glass and CO2 lasers used in these demonstrations had pulse energies of several hundred Joules. Optical breakdown with high-energy nanosecond (or longer) laser pulses i...
متن کاملPlasma luminescence from femtosecond filaments in air: evidence for impact excitation with circularly polarized light pulses.
Filaments produced in air by intense femtosecond laser pulses emit UV luminescence from excited N(2) and N(2)(+) molecules. We report on a strong dependence at high intensities (I≥1.4×10(14) W/cm(2)) of this luminescence with the polarization state of the incident laser pulses. We attribute this effect to the onset of new impact excitation channels from energetic electrons produced with circul...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Optics express
دوره 14 2 شماره
صفحات -
تاریخ انتشار 2006