Early-stage plasma dynamics with air ionization during ultrashort laser ablation of metal

Hu, Wenqian; Shin, Yung C.; King, Galen
September 2011
Physics of Plasmas;Sep2011, Vol. 18 Issue 9, p093302
Academic Journal
In this study, the early-stage plasma evolution generated by an ultrashort laser pulse is investigated through pump-probe shadowgraph measurements and simulations. The measurements are performed to show the evolution of the plasma front, while the simulation model is used to further investigate the evolution process and mechanism. Specifically, the laser pulse propagation in air is simulated using the beam propagation method with the slowly varying envelope approximation. The lattice dynamics, the electron dynamics and the multi-scattering event, and the evolution of charged particles (free electrons and ions), are simulated using a molecular dynamics method, a Monte Carlo method, and a particle-in-cell method, respectively. With this simulation model, the refractive index and plasma evolutions are calculated and compared with measured results to validate the simulation model. Different plasma expansion processes, caused by the air ionization, are found with the focal point slightly above and below the target. Air ionization occurs in both cases, but their primary mechanisms are shown to be different.


Related Articles

  • Cross-correlation measurement of ultrashort soft x-ray pulse emitted from femtosecond laser-produced plasma using optical field-induced ionization. Oguri, Katsuya; Nakano, Hidetoshi; Nishikawa, Tadashi; Uesugi, Naoshi // Applied Physics Letters;12/31/2001, Vol. 79 Issue 27, p4506 

    We propose a cross-correlation technique for measuring ultrashort soft x-ray pulse shapes using the rapid increase in Kr[sup +] ion density caused by optical field-induced ionization, which operates as an ultrafast x-ray absorption switch. Using this technique, we measured the shape of a soft...

  • Toward attosecond metrology. Hentschel, Michael; Kienberger, Reinhard; Drescher, Markus; Corkum, Paul; Krausz, Ferenc // AIP Conference Proceedings;2002, Vol. 611 Issue 1, p56 

    Ultrashort-pulse lasers constitute the fastest probes available for tracing transitions between different states of matter. They allow measuring time intervals on a femtosecond time scale and provide access to fundamental physical, chemical and biological processes on a microscopic scale in the...

  • Analysis of the nonlinear absorption mechanisms in ablation of transparent materials by high-intensity and ultrashort laser pulses. Zavestovskaya, Irina N.; Eliseev, Peter G.; Krokhin, Oleg N.; Men'kova, Natalia A. // Applied Physics A: Materials Science & Processing;Sep2008, Vol. 92 Issue 4, p903 

    The mechanisms of nonlinear absorption in transparent materials under irradiation with ultrashort laser pulses are considered theoretically. Nitride semiconductor, sapphire and others transparent dielectrics were investigated. The ablation threshold for these materials is within multi-TW/cm2...

  • Plume dynamics and shielding characteristics of nanosecond scale multiple pulse in carbon ablation. Pathak, Kedar; Povitsky, Alex // Journal of Applied Physics;Dec2008, Vol. 104 Issue 11, p113108 

    The behavior of ablated plumes produced by nanosecond scale multiple laser pulses typical for carbon ablation is studied in order to understand the plume expansion dynamics and shielding effect of plume with special interest to ionization of plumes. The patterns of a planar plume (typical for...

  • Substrate dependence of ion motion in femtosecond laser ablation cloud observed by planar laser-induced fluorescence. Matsuo, Y.; Kurata-Nishimura, M.; Kobayashi, T.; Kato, T.; Okamura-Oho, Y.; Sano, T.; Hayashizaki, Y.; Kawai, J. // Applied Physics A: Materials Science & Processing;Sep2008, Vol. 92 Issue 4, p993 

    We have observed the motion of Sm+ ions as well as Sm atoms produced by femtosecond laser ablation of a solidified samarium solution sample on substrates by using a planar laser-induced fluorescence method. Kinetic energies of both Sm+ ions and Sm atoms increase as the electrical conductivity of...

  • Ionization dynamics of iron plumes generated by laser ablation versus a laser-ablation-assisted-plasma discharge ion source. Lash, J. S.; Gilgenbach, R. M.; Spindler, H. L. // Journal of Applied Physics;3/1/1996, Vol. 79 Issue 5, p2287 

    Presents information on a study that characterized the ionization dynamics produced in the KrF excimer laser ablation of iron and a laser-ablation-assisted plasma discharge ion source by a dye-laser-based resonant ultraviolet interferometry diagnostic. Experimental procedures; Results and...

  • Impact of the laser wavelength on the dynamics of Xe cluster plasma produced by an intense ultrashort laser pulse. Petrov, G. M.; Davis, J. // Physics of Plasmas;Mar2006, Vol. 13 Issue 3, p033106 

    The dynamics of Xe clusters irradiated by a high intensity subpicosecond laser pulse is investigated through a relativistic time-dependent three-dimensional particle simulation model. In order to explore the effect of transition from underdense to overdense plasma, we performed calculations for...

  • Study of intense femtosecond laser propagation into a dense Ar gas and cluster jet. Caillaud, T.; Blasco, F.; Bonté, C.; Dorchies, F.; Mora, P. // Physics of Plasmas;Mar2006, Vol. 13 Issue 3, p033105 

    The propagation of an intense (up to 1017 W/cm2) and short laser pulse (down to 40 fs) is studied through a well characterized high density Ar cluster jet obtained at the output of a supersonic nozzle. The x-ray emission from the irradiated clusters is measured as a function of the focusing...

  • Simulation of Double-Pulse Laser Ablation. Povarnitsyn, Mikhail E.; Itina, Tatian E.; Khishchenko, Konstantin V.; Levashov, Pavel R. // AIP Conference Proceedings;10/8/2010, Vol. 1278 Issue 1, p635 

    We investigate the physical reasons of a strange decrease in the ablation depth observed in femtosecond double-pulse experiments with increasing delay between the pulses. Two ultrashort pulses of the same energy produce the crater which is less than that created by a single pulse....


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics