Nanoscale confinement of energy deposition in glass by double ultrafast Bessel pulses

Ultrafast laser pulses spatially shaped as Bessel beams in dielectrics create high aspect ratio plasma channels whose relaxation can lead to the formation of nanochannels. We report a strong enhancement of the nanochannel drilling efficiency with illumination by double pulses separated by a delay between 10 and 500 ps. This enables the formation of nanochannels with diameters down to 100 nm. Experimental absorption measurements demonstrate that the increase of drilling efficiency is due to an increase of the confinement of the energy deposition. Nanochannel formation corresponds to a drastic change in absorption of the second pulse, demonstrating the occurrence of a phase change produced by the first pulse. This creates a highly absorbing, long-living state. Our measurements show that it is compatible with the semi-metallization of warm dense glass which takes place within a timescale of <10 ps after the first laser pulse illumination.

A new approach for sustained and efficient H2 photoproduction by Chlamydomonas reinhardtii

Pulse-illumination re-directs photosynthetic electron flow destined for CO2 fixation to [FeFe]-hydrogenase, thus sustaining algal H2 photoproduction for 70 hours.

Plasmon-driven sub-picosecond breathing of metal nanoparticles

We report the first real-time computational study that shows evidence of sub-picosecond beathing oscillations in metal nanoparticles under strong laser pulse illumination.