Spectrum of laser light scattered by nanoparticles in an ablation-induced cavitation bubble

Abstract

The spectrum of the laser light scattered by nanoparticles in a cavitation bubble, which was induced by laser ablation of a titanium target in water, was measured using a triple-grating spectrograph. The scattered laser light observed at 100 $$\upmu $$ s after laser ablation had no wavelength-shifted component, suggesting that nanoparticles at this delay time were metallic. The wavelength-shifted component was observed in the spectrum at a delay time of 200 $$\upmu $$ s, suggesting the formation of oxidized nanoparticles. However, we observed no peaks in the spectrum of the scattered laser light in the present in situ laser-light scattering experiment. On the other hand, we observed clear peaks in the Raman spectrum of synthesized nanoparticles. The experimental results suggest slow crystallization of nanoparticles in liquid in liquid-phase laser ablation.