We developed a new method for synthesizing atomically monodisperse Au ₁₅ nanoclusters stabilized with glutathione molecules, and investigated their nonlinear optical (NLO) properties after two-photon absorption.

We demonstrate that the tuning of the light emission from red to blue in dihydrolipoic acid (DHLA) capped Ag ₂₉ nanoclusters can be trigged with one and two photon excitations.

We report a simple synthesis of silver:glutathione (Ag:SG) clusters using a cyclic reduction under oxidative conditions. Two syntheses are described which lead to solutions containing well-defined Ag₃₁(SG)₁₉ and Ag₁₅(SG)₁₁ clusters that have been characterized by mass spectrometry. The optical properties of silver:glutathione (Ag:SG) cluster solutions have been investigated experimentally. In particular, the solution containing Ag₁₅(SG)₁₁ clusters shows a bright and photostable emission. For Ag₃₁(SG)₁₉ and Ag₁₅(SG)₁₁ clusters, the comparison of experimental findings with DFT and TDDFT calculations allowed us to reveal the structural and electronic properties of such low nuclearity liganded silver clusters.

Ligated silver and gold nanoclusters belonging to a non-scalable size regime with molecular-like discrete electronic states represent an emerging class of extremely interesting optical materials.

Random lasers are a particular class of optical devices where the optical feedback is provided by scattering media. In this review, we discuss recent progress and prospects of random lasers using advanced materials.