Linear and Nonlinear Optical Response of Mie-Resonant Si Nanoparticles and Its Modification Induced by Femtosecond Irradiation Post-Treatment

Silicon nanoparticles with Mie resonances are among the most prospective building blocks for state-of-the-art all-dielectric metasurfaces. Here we focus on linear and nonlinear optical responses of silicon nanoparticles printed by laser-induced transfer from silicon-on-insulator wafer. Second-harmonic generation and broadband multiphoton-absorption-induced luminescence are studied as a function of pump wavelength. The key role of magnetic quadrupole Mie resonances in the nonlinear optical response from silicon nanoparticles is revealed. We also show the influence of Si nanoparticle shape and structure modification, realized by additional femtosecond laser irradiation, on their linear and nonlinear optical properties.