Few-cycle laser pulse characterization on-target using high-harmonic generation from nano-scale solids.

We demonstrate high-harmonic generation for the time-domain observation of the electric field (HHG-TOE) and use it to measure the waveform of ultrashort mid-infrared (MIR) laser pulses interacting with ZnO thin-films or WS monolayers. The working principle relies on perturbing HHG in solids with a weak replica of the pump pulse. We measure the duration of few-cycle pulses at 3200 nm, in reasonable agreement with the results of established pulse characterization techniques.

Two phase-matching regimes in high-order harmonic generation.

High-order harmonic generation (HHG) provides scalable sources of coherent extreme ultraviolet radiation with pulse duration down to the attosecond time scale. Efficient HHG requires the constructive interplay between microscopic and macroscopic effects in the generation volume, which can be achieved over a large range of experimental parameters from the driving field properties to those of the generating medium. Here, we present a systematic study of the harmonic yield as a function of gas pressure and medium length.

Photo-ionization initiated differential ultrafast charge migration: impacts of molecular symmetries and tautomeric forms.

Photo-ionization induced ultrafast electron dynamics is considered as a precursor for the slower nuclear dynamics associated with molecular dissociation. Here, using the multielectron wave-packet propagation method, we study the overall many-electron dynamics, triggered by ionizing the outer-valence orbitals of different tautomers for a prototype molecule with more than one symmetry element. From the time evolution of the initially created averaged hole density of each system, we identify distinctly different charge dynamics responses in the tautomers.

The unique carnation stunt-associated pararetroviroid.

The discovery and description of a pararetroviroid associated with carnation stunt was one of the most outstanding achievements gained by the research team directed by Ricardo Flores, as it opened up a whole new world in plant virology and quickly led to the identification of further viroid diseases. The carnation stunt-associated viroid-like RNA has been proved to exist in both RNA and DNA form, a discovery that pointed to new ways of studying the co-evolution of plants and viroid-like RNAs. This paper aims to summarise the scientific work of Ricardo Flores, a source of inspiration to both present and future generations of scientists.

Bioeconomy: Biomass and biomass-based energy supply and demand.

This paper addresses the challenges of the transition from a fossil fuel-dependent to a bio-based economy and implications related to the production of food, feed, bioenergy and other bio-based materials. The objective is to provide a comprehensive review of global biomass and biomass-based energy supplies and demand, with particular attention to the EU. Furthermore, factors related to setting priorities in the use of non-food biomass are discussed, as food security will remain the top priority.