We have used a commercially available liquid-crystal spatial light modulator within a reflective optics pulse-shaping apparatus to shape ultrashort pulses with temporal resolution approaching 10 fs. Using the spatial light modulator as a phase modulator, we produce a variety of complex ultrafast waveforms, including odd pulses, high repetition rate (.23 THz) pulse trains, and asymmetric pulse t...

We study the ionization dynamics of Ar clusters exposed to ultrashort near-infrared (NIR) laser pulses for intensities well below the threshold at which tunnel ionization ignites nanoplasma formation. We find that the emission of highly charged ions up to Ar^{8+} can be switched on with unit contrast by generating only a few seed electrons with an ultrashort extreme-ultraviolet (XUV) pulse prio...

Autocorrelation is a common method to estimate the duration of ultrashort laser pulses. In the ultraviolet (UV) regime it is challenging to employ the process of second-harmonic generation, most prominently due to absorption in nonlinear crystals at very short wavelengths. Here we show how to utilize spontaneous parametric down-conversion (SPDC) to generate an autocorrelation signal in the infr...

A comparative study of the effect of ultrashort (0.5 ps) and short (15 ns) pulses on the laser forward transfer of DNA molecules is presented in this paper. We use femtosecond laser pulses to directly print a wide range of biomaterials, in complicated patterns and structures. The ultrashort laser pulses reduce the thermal effects, thus allowing the effective deposition of sensitive biomaterials...

We describe a transparent dielectric grating accelerator structure that is designed for ultrashort laser pulse operation. The structure is based on the principle of periodic field reversal to achieve phase synchronicity for relativistic particles; however, to preserve ultrashort pulse operation it does not resonate the laser field in the vacuum channel. The geometry of the structure appears wel...

The filamentation of ultrashort pulses in air is investigated theoretically and experimentally. From the theoretical point of view, beam propagation is shown to be driven by the interplay between random nucleation of small-scale cells and relaxation to long waveguides. After a transient stage along which they vary in location and in amplitude, filaments triggered by an isotropic noise are confi...

Ultrashort optical pulses are integral to various fields. Thus, the characterization of these pulses is crucial in understanding the results of experiments and applications using them. A diagnostic for laser systems was created to determine the shapes of ultrashort optical pulses using the principle of spectral shearing interferometry (SSI). By strongly chirping an optical pulse using a pair of...

The Hawking effect can be rederived in terms of two-point functions and in such a way that it makes it possible to estimate, within the conventional semiclassical theory, the contribution of ultrashort distances to the Planckian spectrum. For Schwarzschild black holes of three solar masses the analysis shows that Hawking radiation is very robust up to frequencies of 96TH or 270TH for bosons and...

Hervé Leblond, David Kremer, and Dumitru Mihalache Laboratoire de Photonique d’Angers, Université d’Angers, 2 Bd. Lavoisier, 49045 Angers Cedex 01, France Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH), 407 Atomistilor, Magurele-Bucharest, 077125, Romania Academy of Romanian Scientists, 54 Splaiul Independentei, Bucharest 050094, Romania Abstract By using a reduc...