Z-scan technique for nonlinear optical characterization of bimetallic Au/Pd nanoparticles

• Autores: R. Gutiérrez, J. Jiménez, J. Sánchez, Z. Correa
• Localización: Ciencias Naturales y Exactas Handbook: Congreso Interdisciplinario de Cuerpos Académicos / coord. por Marcos Rodríguez Sánchez, José Alfredo Aguirre Puente, 2013, ISBN 978-607-8324-06-4, págs. 265-277
• Idioma: inglés
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• Resumen

  • In this paper we present the nonlinear optical characterization of Au/Pd nanoparticles in order to obtain the nonlinear refractive indices using the Z-scan technique. The experiments were performed using a 514 nm laser beam Ar +, with 14Hz of modulation frequency, as excitation source. By using a lens the excitation beam was focused to a small spot and the sample was moved across the focal region along the z axis by a motorized translation stage. Seven samples with different concentration ratio of Au/Pd nanoparticles were prepared by simultaneous reduction of gold and palladium ions in presence of poly (Nvinyl- 2-pirrolidone) (PVP) using ethanol as a reducing agent. In this work, we report the application of the Z-scan technique, to generate optical transmission of laser light as a function of the z position for solutions containing bimetallic nanoparticles of Au (core) / Pd (shell) with average sizes ranging from 3 to 5 nm. The magnitude of the obtained nonlinear refractive index was in the order of 10-7 to 10-8 cm 2/W. Our results show that the nonlinear refractive index has a nonlinear behavior when the (Au/Pd) ratio was increased.