The mechanisms governing generation and amplification of laser-driven electromagnetic pulses (EMPs) in the picosecond (ps) regime remain insufficiently understood. Here, we present a unified theoretical and experimental framework that demonstrates dual-picosecond laser irradiation of solid targets can synergistically enhance EMP emission. By integrating particle-in-cell simulations with three-dimensional electromagnetic modeling, we reveal that the increasing laser focal power density amplifies hot electron emission and strengthens neutralization currents, leading to giant EMP radiations. Experimentally, we validate these predictions at the XG-III and SG-II U picosecond petawatt laser facilities, achieving a record-breaking EMP field strength of 3.08 MV/m – substantially exceeding previously reported values from ps-laser–solid interactions. Furthermore, we demonstrate that EMP characteristics can be precisely tuned via laser and target parameters, enabling controllable, high-field electromagnetic sources. Our findings provide deep insight into the physics of laser-driven EMP amplification and establish a robust platform for developing next-generation high-intensity electromagnetic emitters.

The generation of intense radio-frequency and microwave electromagnetic pulses (EMPs) by the interaction of a high-power laser with a target is an interesting phenomenon, the exact mechanisms of which remain inadequately explained. In this paper we present a detailed characterization of the EMP emission at a sub-nanosecond kilojoule laser facility, the Prague Asterix Laser System. The EMPs were detected using a comprehensive set of broadband diagnostics including B-dot and D-dot probes, various antennas, target current and voltage probes and oscilloscopes with 100 and 128 GS/s sampling. Measurements show that the EMP spectrum was strongly dependent on the laser energy: the maximum frequency of the spectrum and the frequency of the spectrum centroid increased with increasing laser beam energy in the signals from all detectors used. The highest observed frequencies exceeded 9 GHz. The amplitude and energy of the detected EMP signals were scaled as a function of laser energy, power and number of emitted electrons.

Tightly focused proton beams generated from helical coil targets have been shown to be highly collimated across small distances, and display characteristic spectral bunching. We show, for the first time, proton spectra from such targets at high resolution via a Thomson parabola spectrometer. The proton spectral peaks reach energies above 50 MeV, with cutoffs approaching 70 MeV and particle numbers greater than 10${}^{10}$. The spectral bunch width has also been measured as low as approximately 8.5 MeV (17% energy spread). The proton beam pointing and divergence measured at metre-scale distances are found to be stable with the average pointing stability below 10 mrad, and average half-angle beam divergences of approximately 6 mrad. Evidence of the influence of the final turn of the coil on beam pointing over long distances is also presented, corroborated by particle tracing simulations, indicating the scope for further improvement and control of the beam pointing with modifying target parameters.

Premature infants have a risk of neurodevelopmental deficits. Little is known, however, about how retinopathy of prematurity (ROP) affects visual motor integration (VMI), which is necessary for both fine motor skills and further school abilities. Due to the systemic escape of bevacizumab in the treatment of ROP, concerns regarding the long-term neurodevelopmental effect of the drug have arisen. The aim is to evaluate VMI and motor development long-term outcomes after intravitreal bevacizumab (IVB) injection and laser treatment for ROP. Two groups of premature children were included: Bevacizumab group – 16 premature children who received IVB treatment and laser group – 23 premature children who underwent laser photocoagulation treatment in this single center cross-sectional study. At 2–6 years of age, VMI (Beery–Buktenica Developmental Test), motor development (Peabody Developmental Motor Scales-2), visual acuity, and refractive status were assessed. The incidence of abnormal visual function was significantly higher in bevacizumab group than in laser group (p = 0.022). The incidence of abnormal VMI skill was significantly higher in bevacizumab group than in laser group (p = 0.024). Incidences of abnormal gross, fine, and total motor skills were significantly higher in bevacizumab group compared to laser group (p < 0.05). Premature children who received bevacizumab for ROP demonstrated significantly lower VMI and motor development features than those with laser treatment at preschool age. Although our results suggest the relevance of bevacizumab injection in impaired VMI and motor development outcomes, general level of sickness rather than treatment might be the cause of delayed motor development.

The production of broadband, terawatt terahertz (THz) pulses has been demonstrated by irradiating relativistic lasers on solid targets. However, the generation of extremely powerful, narrow-band and frequency-tunable THz pulses remains a challenge. Here, we present a novel approach for such THz pulses, in which a plasma wiggler is elaborated by a table-top laser and a near-critical density plasma. In such a wiggler, the laser-accelerated electrons emit THz radiations with a period closely related to the plasma thickness. The theoretical model and numerical simulations predict that a THz pulse with a laser–THz energy conversion of over 2.0%, an ultra-strong field exceeding 80 GV/m, a divergence angle of approximately 20° and a center frequency tunable from 4.4 to 1.5 THz can be generated from a laser of 430 mJ. Furthermore, we demonstrate that this method can work across a wide range of laser and plasma parameters, offering potential for future applications with extremely powerful THz pulses.

Exploiting high-energy electron beams colliding into high-intensity laser pulses brings an opportunity to reach high values of the dimensionless rest-frame acceleration $\chi$ and thereby invoke processes described by strong-field quantum electrodynamics (SFQED). Measuring deviations from the results of Furry-picture perturbation theory in SFQED at high $\chi$ can be valuable for testing existing predictions, as well as for guiding further theoretical developments. Nevertheless, such experimental measurements are challenging due to the probabilistic nature of the interaction processes, dominating signals of low-$\chi$ interactions and limited capabilities to control and measure the alignment and synchronization in such collision experiments. Here we elaborate a methodology of using approximate Bayesian computations for drawing statistical inferences based on the results of many repeated experiments despite partially unknown collision parameters that vary between experiments. As a proof-of-principle, we consider the problem of inferring the effective mass change due to coupling with the strong-field environment.