Multi-µJ coherent extreme ultraviolet source generated from carbon using the plasma harmonic method

Abstract

We demonstrate intense high-order harmonic generation from plasma that is created from different carbon targets. We obtain high-order harmonic energy in the multi-microjoule range for each harmonic order from the 11th to the 17th harmonic. By analyzing the target morphology and the plasma composition, we conclude that the intense harmonics from the bulk carbon targets originate from nanoparticles target.

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

“…In addition, the efficiency of conversion to an individual (resonantly enhanced) high-order harmonic approached 10 À4 [37,38]. Recent studies of carbon plasma have revealed that the high-order harmonics from this medium can also achieve 10 À4 conversion efficiency, thus reaching the microjoule level of pulse energies for these XUV sources [39,40]. The majority of these parameters are at the same level as the results obtained in gas media.…”

“…Below, the most recent developments and some fresh approaches, experimental schemes and ideas are described, which could considerably push this field toward the dramatic improvement of the output characteristics of harmonics. The intense HHG from plasma that is created from different carbon targets was demonstrated recently in [39]. A high-order harmonic energy in the multimicrojoule range for each harmonic order from the 11th to the 17th harmonic was obtained.…”

“…The disadvantage of using nanoparticle and film targets is the instability of the harmonic signal, which considerably varies from shot to shot, and even disappears after a few laser shots if the target is not moved. On the contrary, in [39] it was found for the first time that carbon bulk targets can generate intense harmonics, with an intensity comparable to the nanoparticle or C 60 film targets. The scanning electron microscope (SEM) image of plasma debris from a carbon target revealed that the plasma plumes contain nanoparticles with sizes varying between 100 nm and 300 nm.…”

“…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.…”

High-order harmonic generation during propagation of the double-pulse beam through the drilled thin films

“…It means that the harmonic generation was carried out during interaction of the laser pulse with small amount of the potential emitters of coherent radiation. Previous studies of plasma harmonics were performed using significantly longer plasma plumes (0.5-5 mm) [13][14][15][16][17][18][19][20]. Further, the short delay between pulses (8 ns) did not allow the whole cloud of ablated particles to propagate the distance equal to the radius of drilled hole (*40 lm).…”