Abstract
This paper examines ultrafast laser-induced plasma generation in dielectrics by modeling ionization and pulse propagation in glass. Photoionization models for solids predict that the multi-photon ionization rate should increase for near-UV frequencies when compared to those in the visible or near-IR. Conversely, the frequency dependence of a Drude-type absorption by free electrons can produce an increased ionization yield through avalanching for frequencies in the IR. The simulations presented in this paper reveal how such frequency-dependent models influence the plasma formation during nonlinear pulse propagation in fused silica. It is further shown by a multi-rate equation model that the contribution from avalanching, when properly delayed, is reduced by an order of magnitude at near-IR frequencies throughout the propagation. A modified multi-rate equation is then introduced to model combinations of ultrashort high-frequency and low-frequency pulses that can maximize plasma generation while operating at the lowest possible fluences.
© 2014 Optical Society of America
Full Article | PDF ArticleMore Like This
E. G. Gamaly and A. V. Rode
J. Opt. Soc. Am. B 31(11) C36-C43 (2014)
Carles Milián, Amélie Jarnac, Yohann Brelet, Vytautas Jukna, Aurélien Houard, André Mysyrowicz, and Arnaud Couairon
J. Opt. Soc. Am. B 31(11) 2829-2837 (2014)
Ya Tian, Cheng Gong, Deyi Kong, and Xiangming Hu
J. Opt. Soc. Am. B 39(9) 2435-2442 (2022)