Ablation of nanoparticles and efficient harmonic generation using a 1-kHz laser

We report on high-order-harmonic generation in nanoparticle-containing laser ablation plasmas using a Ti:sapphire driving laser at a repetition rate of 1 kHz and on the relation of the harmonic signals with the morphological and spectroscopic characteristics of the ablation deposits. The study of the deposits has allowed the definition of ablation conditions, leading to the generation of a plasma containing nanoparticles of similar sizes to the ones used as target material. The corresponding plasma plumes lead to efficient conversion of the IR photons towards the short-wavelength range through high-order harmonic generation and show superior performance to those corresponding to bulk targets of the same metallic element.