Strong Third-order Optical Nonlinearities of the Ag, Ni, Ti, and Co Nanoparticles Synthesized During Laser Ablation of Bulk Metals in Liquids

摘要

Laser ablation of the materials immersed in liquid environment has been established as an advanced method for formation of the stable nanoparticles, especially those which cannot be synthesized by chemical methods. We review the studies of four metal (Ag, Ti, Co, Ni) nanoparticles synthesized during laser ablation in different liquids. The correlation between strong nonlinear optical response of silver nanoparticles out of plasmon resonance and efficient third harmonic generation in the plasmas containing silver nanoparticles is discussed. The change of sign of the nonlinear refraction with variation of the wavelength and duration of probe laser pulses is analyzed. The studies of third-order nonlinear optical processes (saturable absorption, reverse saturable absorption, two-photon absorption and nonlinear refraction) in the titanium and cobalt nanoparticles synthesized by laser ablation of bulk materials in water, toluene and ethylene glycol are discussed. The concurrence of different nonlinear absorption processes in nanoparticle-containing suspensions is analyzed. We discuss the two-photon absorption and nonlinear refraction studies of the nickel nanoparticles in water using femtosecond laser pulses at 400 and 800 nm. Third harmonic generation from the Ni nanoparticles contained plasma using picosecond and femtosecond pulses as heating radiation and femtosecond probe pulses is analyzed.