Ablation and optical third-order nonlinearities in Ag nanoparticles
Por:
Torres-Torres C., Peréa-López N., Reyes-Esqueda J.A., Rodríguez-Fernández L., Crespo-Sosa A., Cheang-Wong J.C., Oliver A.
Publicada:
1 ene 2010
Resumen:
The optical damage associated with high intensity laser excitation of silver nanoparticles (NPs) was studied. In order to investigate the mechanisms of optical nonlinearity of a nanocomposite and their relation with its ablation threshold, a high-purity silica sample implanted with Ag ions was exposed to different nanosecond and picosecond laser irradiations. The magnitude and sign of picosecond refractive and absorptive nonlinearities were measured near and far from the surface plasmon resonance (SPR) of the Ag NPs with a self-diffraction technique. Saturable optical absorption and electronic polarization related to self-focusing were identified. Linear absorption is the main process involved in nanosecond laser ablation, but nonlinearities are important for ultrashort picosecond pulses when the absorptive process become significantly dependent on the irradiance. We estimated that near the resonance, picosecond intraband transitions allow an expanded distribution of energy among the NPs, in comparison to the energy distribution resulting in a case of far from resonance, when the most important absorption takes place in silica. We measured important differences in the ablation threshold and we estimated that the high selectiveness of the SPR of Ag NPs as well as their corresponding optical nonlinearities can be strongly significant for laser-induced controlled explosions, with potential applications for biomedical photothermal processes. © 2010 Torres-Torres et al, publisher and licensee Dove Medical Press Ltd.
Filiaciones:
Torres-Torres C.:
Section of Graduate Studies and Research, School of Mechanical and Electrical Engineering, National Polytechnic Institute, Zacatenco, Distrito Federal, Mexico
Peréa-López N.:
Laboratory for Nanoscience, Nanotechnology Research and Advanced Materials Department, IPICYT, Camino a la Presa San Jose, San Luis Potosi, Mexico
Reyes-Esqueda J.A.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico
Rodríguez-Fernández L.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico
Crespo-Sosa A.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico
Cheang-Wong J.C.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico
Oliver A.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 01000, DF, Mexico
All Open Access, Gold
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