Linear and nonlinear optical properties of noble metal nanoparticles and their applications

Abstract

Noble metal nanoparticles chemistry is a domain in rapid expansion and has received great attention in the past two decades, as those objects lead to interesting applications in the fields of catalysis, biosensing, electronics and optics. Linear and nonlinear optical properties of gold and silver nanoparticles of various types such as silver nanoprisms, gold nanochains, alkylamine capped gold nanoparticles and glutathione capped gold clusters were investigated. These nanoparticles displayed exceptional optical limiting effects with thresholds lower than that of carbon nanotube suspension, a benchmark optical limiter. The input fluence and angle dependent scattering measurements suggested that nonlinear scattering played an important role in the observed optical limiting behavior of gold and silver nanoparticles. But the nonlinear optical property of gold clusters (Au25) arises due to the strong two-photon absorption. The two-photon absorption cross section of these gold clusters in water was deduced from the z-scan measurement to be 189 740 GM, which is much higher compared to organic fluorescent dyes and quantum dots. The applications of gold and silver nanoparticles for Optical limiting, Surface enhanced Raman scattering (SERS), bio-imaging, photo detection and printable electronics have been studied.