Vertical decorative line
Research Center for Complex Molecular Systems and Biomolecules
Center for Biomolecules and Complex Molecular Systems   
Supported by the Ministry of Education, Czech Republic      
Decorative element
Decorative element
Decorative element Research | Papers | People | Events | Archive | Teach | Contact   
Decorative element
Empty gif
Empty space gif.
Abstract of the article
Empty gif Empty gif
Nonresonant ionization of oxygen molecules by femtosecond pulses: plasma dynamics studied by timeresolved terahertz spectroscopy.

Mics, Z.; Kadlec, F.; Kuzel, P. etc., Journal of Chemical Physics, 123 [10] 104310 (2005)

We show that optical pump-terahertz probe spectroscopy is a direct experimental tool for exploring laser-induced ionization and plasma formation in gases. Plasma was produced in gaseous oxygen by focused amplified femtosecond pulses. The ionization mechanisms at 400- and 800-nm excitation wavelengths differ significantly being primarily of a multiphoton character in the former case and a strong-field process in the latter case. The generation of the plasma in the focal volume of the laser and its expansion on subnanosecond time scale is directly monitored through its density-dependent susceptibility. A Drude model used to evaluate the plasma densities and electron-scattering rates successfully captures the observations for a wide range of pump intensities. In addition, rotational fingerprints of molecular and ionic species were also observed in the spectra.


<< Go back
Empty space gif.
Empty gif
Decorative element