Numerical Analysis of Ultra-Short Laser Interactions with Dielectric Materials

Abstract : Laser-induced electronic excitation, absorption and relaxation are the key issues in ultra-short laser interactions with dielectric materials. To numerically analyze these processes, a detailed non-equilibrium model is developed [1] based on the kinetic Boltzmann equations without any appeal to the classical Drude model. The calculations yield not only free carriers density, but also their energy distribution allowing a better analysis of the role of avalanche ionization. The calculations performed reveal a remarkable effect of the laser-field on collision frequencies resulting in smaller free-carriers absorption than the one predicted by commonly used rate-equation models. In addition, modeling clearly demonstrates laser intensity limits for the applicability of Keldysh's equation for the photoionization process [2]. Furthermore, both electron-electron and electron-phonon relaxation are examined, and the energy of the electron sub-system is investigated as a function of laser fluence and pulse duration. Because efficient bond breaking requires energy, these calculations provide the required thresholds. The dependency of the calculated fluence threshold on laser pulse duration is compared with the available experimental data. The obtained results also explain several recent pump-probe experiments. The developed model is useful for many laser applications including high precision in laser treatment, laser-assisted atomic probe tomography, and for the development of new powerful laser systems. [1] N. S. Shcheblanov and T. E. Itina, Appl. Phys. A DOI: 10.1007/s00339-012-7130-0 (2012) [2] N. S. Shcheblanov and T. E. Itina, submitted
Type de document :
Communication dans un congrès
12th International Conference on Laser Ablation, COLA 2013, Ischia, Italy, Oct 2013, Ischia, Italy. p3-11
Liste complète des métadonnées

https://hal-ujm.archives-ouvertes.fr/ujm-00878673
Contributeur : Tatiana Itina <>
Soumis le : mercredi 30 octobre 2013 - 15:09:00
Dernière modification le : mercredi 25 juillet 2018 - 14:05:31

Identifiants

  • HAL Id : ujm-00878673, version 1

Collections

Citation

Nikita Shcheblanov, Tatiana Itina. Numerical Analysis of Ultra-Short Laser Interactions with Dielectric Materials. 12th International Conference on Laser Ablation, COLA 2013, Ischia, Italy, Oct 2013, Ischia, Italy. p3-11. 〈ujm-00878673〉

Partager

Métriques

Consultations de la notice

81