Influence of C60 morphology on high-order harmonic generation enhancement in fullerene-containing plasma

Abstract

The morphologies of the fullerene targets and the ablated fullerenes to determine the optimal conditions of excitation of the C60-containing targets have been analyzed. The optimization of fullerene-containing plasma conditions allowed the enhanced harmonic generation in these plasmas using laser radiation of different wavelengths, pulse durations, and phase modulation. A comparison between the harmonic generation in single-atom/ion-containing plasmas (using bulk carbon, silver, and indium targets) and fullerene-rich plasma plumes showed better conversion efficiency for the latter medium. The influence of phase modulation of the fundamental radiation in fullerene plasmas on the spectral properties of harmonics has been studied.

Harmonic generation in laser-produced plasmas containing atoms, ions and clusters: a review

“…Note that harmonic cut-offs in the cases of single-colour and two-colour pumps were not significantly different. The reported conversion efficiency from fullerene plasma (5 Â 10 À5 [44,45,67]) can also be attributed to the carbon aerogel plasma, because the experiments analysed in this work have demonstrated the similarity in the HHG conversion efficiencies in these two plasma plumes.…”

“…Among them are the studies of harmonics from clusters using the ablation of commercially available nanoparticles [42,43], fullerenes [44][45][46] and carbon nanotubes [47], resonanceenhanced features of odd and even harmonics [48], generation of extremely broadband high-order harmonics [49], application of high pulse repetition rate laser sources and ultrashort pulses for HHG in plasma plumes [32], observation of quantum path signatures in the harmonic spectra from various plasmas [33], enhancement of harmonics from in situ-produced clusters [50], development of few theoretical approaches describing the observed peculiarities of resonance-enhanced harmonics [51][52][53][54][55][56], emergence of a 'second' plateau in the harmonic distribution [57], development of the two-colour pump schemes for plasma-induced harmonics [58,59], observation of extremely strong HHG in carbon-contained plasmas [39,40], proposals for the quasi-phase matching in plasma plumes [60], observation of the attosecond nature of pulse duration of the plasma-induced harmonics [61], etc. Most of these findings will be discussed in the present review.…”

“…Note the absence of reports on higher-order harmonics in fullerenes until recent studies where the application of laser ablation allowed the production of plasma plumes containing a considerable amount of C 60 particles for efficient conversion of the short laser pulses (i.e. of a few tens of femtoseconds) in the XUV range [44,45,67]. The conversion efficiency for the odd and even harmonics in the vicinity of SPR of the C 60 -containing plasma (40-70 nm) was estimated to be in the range of 10 À5 -10 À4 .…”

“…The important issue of these and other [30,39,40,[44][45][46][47]67] studies is why carbon-containing plasma plumes allow the generation of intense harmonics. In this and previous sections, we presented a few observations of this phenomenon.…”

Endohedral fullerenes: A way to control resonant high-order harmonic generation

“…Recently the enhancement of groups of harmonics was reported during HHG in fullerene-containing plasma plumes [2,[27][28][29]. The enhanced harmonics were observed in the range of the 13th harmonic, which was attributed to the influence of the SPR of neutral C 60 (λ SPR ∼ = 60 nm with 10 nm full width at half maximum).…”