title: Coupling localized plasmonic and photonic modes tailors and boosts ultrafast light modulation by gold nanoparticles.
abstract: Plasmonic nanoparticles offer a broad range of functionalities, owing to their ability to amplify light in the near-field or convert it into heat. However, their ultrafast nonlinear optical response remains too low to envisage all-optical high-rate photonic processing applications. Here, we tackle this challenge by coupling the localized plasmon mode in gold nanoparticles with a localized photonic mode in a 1D resonant cavity. Despite the nonradiative losses, we demonstrate that a strong, reversible, and ultrafast optical modulation can be achieved. By using a light pumping fluence of less than 1 mJ cm(-2), a change of signal transmittance of more than 100% is generated within a few picosecond time scale. The nanoparticle transient optical response is enhanced by a factor of 30 to 40 while its spectral profile is strongly sharpened. The large nonlinear response of such plasmonic cavities could open new opportunities for ultrafast light processing at the nanoscale.
authors: †Laboratoire de Photonique Quantique et Moléculaire, UMR 8537-CNRS, Ecole Normale Supérieure de Cachan, CentraleSupélec, Grande Voie des Vignes, 92295 Châtenay-Malabry CEDEX, France.|§Laboratory of Nanomaterials, National Center for Nanoscience and Technology, Beiyitiao No. 11, Zhongguancun, Beijing 100190, P. R. China.
authors: Xiaoli
authors: X
authors: Wang
authors: ‡Laser Processing Group, Instituto de Óptica, CSIC, Serrano 121, 28006 Madrid, Spain.
authors: Roberta
authors: R
authors: Morea
authors: ‡Laser Processing Group, Instituto de Óptica, CSIC, Serrano 121, 28006 Madrid, Spain.
authors: Jose
authors: J
authors: Gonzalo
authors: †Laboratoire de Photonique Quantique et Moléculaire, UMR 8537-CNRS, Ecole Normale Supérieure de Cachan, CentraleSupélec, Grande Voie des Vignes, 92295 Châtenay-Malabry CEDEX, France.
authors: Bruno
authors: B
authors: Palpant
keywords: gold nanoparticles; nonlinear optical response; photonic cavity; plasmonics; transient optical response; ultrafast modulation