On the physical contributions to the third-order nonlinear optical response in plasmonic nanocomposites
Por:
Fernández-Hernández R.C., Gleason-Villagran R., Torres-Torres C., Rodríguez-Fernández L., Crespo-Sosa A., Cheang-Wong J.C., López-Suárez A., Rangel-Rojo R., Oliver A., Reyes-Esqueda J.A.
Publicada:
1 dic 2012
Resumen:
Au and Ag isotropic and anisotropic nanocomposites were prepared using the ion implantation technique. Their optical properties were studied at several wavelengths in the optical range 300-800 nm, across their plasmon resonances. The linear regime was characterized by measuring the absorption spectrum and the third-order nonlinear regime by means of the Z-scan technique using a tunable picosecond pulsed laser system (26 ps). Open-aperture Z-scan traces show a superposition of different optical nonlinear absorption (NLA) processes in the whole range studied. We associate these phenomena with the excitation of inter- and intra-band electronic transitions, which contribute with a positive sign to NLA, and to the formation of hot-electrons, which contribute with opposite sign to NLA. Closed-aperture traces for measuring nonlinear refraction (NLR) show different signs for Au and Ag samples, and a change of sign in Au is found when purely inter-band transitions are excited. In this work, for the appropriate wavelength, it is worth remarking on the free-electron response to the exciting light and its strong contribution to the nonlinear optical properties for low (intra-band) and high (hot-electrons) irradiances. © 2012 IOP Publishing Ltd.
Filiaciones:
Fernández-Hernández R.C.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 04510, DF, Mexico
Gleason-Villagran R.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 04510, DF, Mexico
Torres-Torres C.:
Sección de Estudios de Posgrado e Investigación, ESIME-Zacatenco, Instituto Politécnico Nacional, México, D F 07338, Mexico
Rodríguez-Fernández L.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 04510, DF, Mexico
Crespo-Sosa A.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 04510, DF, Mexico
Cheang-Wong J.C.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 04510, DF, Mexico
López-Suárez A.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 04510, DF, Mexico
Rangel-Rojo R.:
Departamento de Óptica, Centro de Investigación Científica y de Educación Superior de Ensenada, Apartado Postal 2732, Ensenada B C 22860, Mexico
Oliver A.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 04510, DF, Mexico
Reyes-Esqueda J.A.:
Univ Nacl Autonoma Mexico, Inst Fis, Mexico City 04510, DF, Mexico
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