Soliton Formation and Superluminality Effect due to Nonlinear Absorption of Femtosecond Laser Pulse Energy by the Medium Containing Nanorods

24th International Laser Physics Workshop

Trofimov, Vyacheslav A.^1 ; Lysak, Tatiana M.^1

Lomonosov Moscow State University, Moscow

119992, Russia^1

关键词: Femtosecond-pulse propagation;    Interaction of laser pulse;    Laser energy absorption;    Laser pulse propagation;    Multi-photon absorption;    Nonlinear absorptions;    Optical radiations;    Physical mechanism;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/691/1/012012/pdf
DOI  :  10.1088/1742-6596/691/1/012012

来源: IOP

【 摘 要 】

We investigate a femtosecond pulse propagation in a medium, containing nanorods, with taking into account the dependence of multi-photon absorption from the aspect ratio of nanorods. Nanorods melting due to the laser energy absorption leads to the non-stationary interaction of laser pulse with the medium and time-dependent nanorod aspect ratio changing. Under certain conditions, we found out the soliton-like mode of a laser pulse propagation and the superluminality effect: acceleration of light (fast light) in comparison with light propagation in a linear medium. We discuss a physical mechanism of superluminality effect for considering laser pulse propagation. Using spatio-temporal analogy, one can see the similarity between the pulse centre evolution along longitudinal coordinate and the beam centre evolution under the infrared optical radiation propagation in a cloud, or fog, which moves across the beam, with taking into account its thermal blooming.