Tuning Optical Nonlinearity of Laser-Ablation-Synthesized Silicon Nanoparticles via Doping Concentration
(a) Diagram of the laser ablation for silicon nanoparticles’ synthesis. (b) SEM images of the silicon nanoparticles; inset: zoom-in image. (c) Particle size distribution of the silicon nanoparticles. (d) Laser plasma plume formation induced by laser ablation at different stages of (1) initial, (2) expansion, and (3) saturation.