Abstract

We study high-order harmonic generation in plasma containing an abundance of indium oxide nanoparticles. We find that harmonics from nanoparticles are intense, with high-order harmonic energy ranging from 6 μJ for the 9^th harmonic to 1 μJ for the 17^th harmonic. However, the harmonic cut-off is at the 21^st order, which is much lower than that observed using solid indium oxide targets. By comparing the harmonic spectrum obtained using solid and nanoparticle indium oxide, we conclude that the intense harmonics from nanoparticles are generated from neutral atoms.

© 2009 Optical Society of America