| Autor: |
Sánchez-García L; Dept. Física de Materiales and Instituto de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, 28049-Madrid, Spain. luisa.bausa@uam.es., Ramírez MO; Dept. Física de Materiales and Instituto de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, 28049-Madrid, Spain. luisa.bausa@uam.es., Tserkezis C; Technical University of Denmark, Department of Photonics Engineering, Ørsteds Plads, Building 343, 2800 Kgs. Lyngby, Denmark., Sole R; Fisica i Cristal·lografia de Materials i Nanomaterials, FiCMA-FiCNA, EMaS, Universitat Rovira i Virgili, Tarragona 43007, Spain., Carvajal JJ; Fisica i Cristal·lografia de Materials i Nanomaterials, FiCMA-FiCNA, EMaS, Universitat Rovira i Virgili, Tarragona 43007, Spain., Aguiló M; Fisica i Cristal·lografia de Materials i Nanomaterials, FiCMA-FiCNA, EMaS, Universitat Rovira i Virgili, Tarragona 43007, Spain., Díaz F; Fisica i Cristal·lografia de Materials i Nanomaterials, FiCMA-FiCNA, EMaS, Universitat Rovira i Virgili, Tarragona 43007, Spain., Bausá LE; Dept. Física de Materiales and Instituto de Materiales Nicolás Cabrera, Universidad Autónoma de Madrid, 28049-Madrid, Spain. luisa.bausa@uam.es. |
| Abstrakt: |
Increasing Yb 3+ absorption efficiency is currently desired in a number of applications including bio-imaging, photovoltaics, near infrared driven photocatalysis or ultra-short pulsed solid-state lasers. In this work, silver nanoparticles, which are connected forming disordered networks, have been self-assembled on Yb 3+ doped RbTiOPO 4 crystals to produce a remarkable enhancement of Yb 3+ absorption, and hence in the photoluminescence of this ion. The results are interpreted taking into account the near-field response of the plasmonic networks, which display strong amplification of the electric field at the maximum of Yb 3+ excitation at around 900 nm, together with the anisotropic character of the Yb 3+ transitions in RbTiOPO 4 . We show that in the near field regime, the scattering of the plasmonic networks produces additional polarization field components to those of the incident field, which allows access to the largest transition dipolar moment of Yb 3+ ions in RbTiOPO 4 . As a result, a much more efficient route for Yb 3+ excitation takes place at the immediacy of the plasmonic networks. This work provides fundamental insights for improving the optical properties of rare earth ions by the suitable design of metallic nanoparticle arrangements, and constitutes a promising step towards the development of new multifunctional solid-state lasers. |
