Surface plasmon resonance dependent third‐order optical nonlinearities of silver nanoplates

A systematic study of the surface plasmon resonance (SPR)‐dependent nonlinear optical response of Ag nanoplates is presented and discussed. The Ag nanoplates were synthesized using the well‐known seed‐mediated growth method. By performing the z‐scan method with a nanosecond laser (532 nm, 5 ns), the optical nonlinearities of the Ag nanoplates, prepared tuning the SPR contribution in the 400–1000 nm range, were determined. The results showed a SPR‐related competition between the saturable absorption and reverse saturable absorption mechanisms, while the nonlinear refraction changed from self‐defocusing to self‐focusing. Furthermore, the scattering effects contribute to determine the nature of the optical limiting response. The observed SPR‐tunable third order optical nonlinearities make Ag nanoplates a suitable candidate to be used in different fields, i.e., laser pulse generation, optical limiting, or bio‐imaging applications.