Application of encapsulated hollow Gold nanocluster targets for high-quality and quasi-monoenergetic ions generation

With persistent progress in ultra-intense laser pulses, Coulomb explosion (CE) of spherical nanoclusters can in principle produce high-quality-quasi-monoenergetic ions. Focusing on using CE framework, in this paper, we have proposed a target scheme to accelerate light/heavy ions’ beam. The scheme relies on encapsulating a hollow Gold nanocluster inside a hollow proton-Carbon (HC) nanosphere. The ability of this suggestion has been simulated by the two-dimensional particle-in-cell code (EPOCH). Simulation results exhibit that a hollow Gold cluster can positively increase the electrons’ extraction. This condition may improve the acceleration of low-divergence H+, C6+, and Au67+ ions. Our simulation shows that at the end of the interaction, for a Gold cluster with an optimal hollow radius of 91.3 nm, the cut-off energy of H+, C6+, and Au67+ are about 54.9 MeV/u, 51.5 MeV/u, and 54.9 MeV/u, respectively. In this case, an increase of about 52% for H+ and 61% for C6+ is obtained, contrast to bare HC hollow nanosphere (i.e., a hollow nanosphere with no cluster), while the relative divergence decreases to 1.38 and 1.86, respectively for H+ and C6+ ions. We have also compared our simulation results with another proposed target structure composed of a void area with an optimum diameter of 70.4 nm between the fully- Gold nanocluster and HC nanosphere. We have exhibited that the results are improved, contrast to bare nanosphere. However, the cut-off energy suppression and angular divergence increase are shown compared with encapsulated hollow Gold nanocluster structure.

The High Energy Density Scientific Instrument at the European XFEL

The European XFEL delivers up to 27000 intense (>1012 photons) pulses per second, of ultrashort (≤50 fs) and transversely coherent X-ray radiation, at a maximum repetition rate of 4.5 MHz. Its unique X-ray beam parameters enable groundbreaking experiments in matter at extreme conditions at the High Energy Density (HED) scientific instrument. The performance of the HED instrument during its first two years of operation, its scientific remit, as well as ongoing installations towards full operation are presented. Scientific goals of HED include the investigation of extreme states of matter created by intense laser pulses, diamond anvil cells, or pulsed magnets, and ultrafast X-ray methods that allow their diagnosis using self-amplified spontaneous emission between 5 and 25 keV, coupled with X-ray monochromators and optional seeded beam operation. The HED instrument provides two target chambers, X-ray spectrometers for emission and scattering, X-ray detectors, and a timing tool to correct for residual timing jitter between laser and X-ray pulses.

High laser induced damage threshold photoresists for nano-imprint and 3D multi-photon lithography

Optics manufacturing technology is predicted to play a major role in the future production of integrated photonic circuits. One of the major drawbacks in the realization of photonic circuits is the damage of optical materials by intense laser pulses. Here, we report on the preparation of a series of organic–inorganic hybrid photoresists that exhibit enhanced laser-induced damage threshold. These photoresists showed to be candidates for the fabrication of micro-optical elements (MOEs) using three-dimensional multiphoton lithography. Moreover, they demonstrate pattern ability by nanoimprint lithography, making them suitable for future mass production of MOEs.

Generation of even and odd high harmonics in resonant metasurfaces using single and multiple ultra-intense laser pulses

High harmonic generation (HHG) opens a window on the fundamental science of strong-field light-mater interaction and serves as a key building block for attosecond optics and metrology. Resonantly enhanced HHG from hot spots in nanostructures is an attractive route to overcoming the well-known limitations of gases and bulk solids. Here, we demonstrate a nanoscale platform for highly efficient HHG driven by intense mid-infrared laser pulses: an ultra-thin resonant gallium phosphide (GaP) metasurface. The wide bandgap and the lack of inversion symmetry of the GaP crystal enable the generation of even and odd harmonics covering a wide range of photon energies between 1.3 and 3 eV with minimal reabsorption. The resonantly enhanced conversion efficiency facilitates single-shot measurements that avoid material damage and pave the way to study the controllable transition between perturbative and non-perturbative regimes of light-matter interactions at the nanoscale.

Research of Interaction between Ultra-Short Ultra-Intense Laser Pulses and Multiple Plasma Layers

In this research, we studied the interaction between the ultra-intense laser and multiple copper layers covered with multiple hydrogen layers. The research conditions are based on the symmetric and asymmetric structure of multilayer copper and hydrogen. It was found that the acceleration obtained from the first copper and hydrogen layer plasma was higher and occurred earlier than the second copper and hydrogen layer plasma. We investigated the spatial distribution and phase-space distribution of copper electrons, copper ions, hydrogen electrons, and hydrogen protons with different widths of the front hydrogen layer and the front copper layer, respectively. Theoretical simulations show that when the ultra-intense laser was irradiated in multiple copper layers coated with multiple hydrogen layers targets, some plasma phase-space distribution varied clearly in the different thicknesses of the first hydrogen layer or first copper layer, while some plasma were not influenced by the thickness of these two layers.