Nonlinear Refraction and Absorption of Ag 29 Nanoclusters: Evidence for Two-Photon Absorption Saturation

Albert Reyna (1) , Isabelle Russier-Antoine (2) , Franck Bertorelle (2) , Emmanuel Benichou (2) , Philippe Dugourd (2) , Rodolphe Antoine (2) , Pierre-Francois Brevet (2) , Cid de Araújo (1)

1 Departamento de Fisica, Universidade Federal de Pernambuco
2 ILM - Institut Lumière Matière [Villeurbanne]

We report the nonlinear absorption and refraction of Ag₂₉ nanocluster aqueous suspensions using the open and closed aperture Z-scan method at 532 nm. The stoichiometry of the atomically precise silver nanoclusters has been determined by mass spectrometry, and their formula is Ag₂₉DHLA₁₂ where the ligand is dihydrolipoic acid (DHLA). Using different concentration of nanoclusters, we observe beyond the expected linear absorption saturation and nonlinear absorption a clear saturation of the nonlinear absorption, a feature so far not described for nanoclusters. The nonlinear refraction is also determined and exhibits a regular behavior with a negative n₂ value. A figure of merit is discussed in view of potential applications.

Mots clés: Saturation; Absorption; Optical properties; Quantum mechanics; Nanoclusters

Domaines: Physique [physics]; Chimie-Physique [physics.chem-ph]; Chimie analytique; Agrégats Moléculaires et Atomiques [physics.atm-clus]

Albert Reyna, Isabelle Russier-Antoine, Franck Bertorelle, Emmanuel Benichou, Philippe Dugourd, et al.. Nonlinear Refraction and Absorption of Ag 29 Nanoclusters: Evidence for Two-Photon Absorption Saturation. Journal of Physical Chemistry C, 2018, 122 (32), pp.18682-18689. ⟨10.1021/acs.jpcc.8b03550⟩. ⟨hal-02108491⟩