Optimal Control of the Strong-Field Ionization of Silver Clusters in Helium Droplets

Abstract

Optimal control techniques combined with femtosecond laser pulse shaping are applied to steer and enhance the strong-field induced emission of highly charged atomic ions from silver clusters embedded in helium nanodroplets. With light fields shaped in amplitude and phase we observe a substantial increase of the Ag${}^{q+}$ yield for $q>10$ when compared to bandwidth-limited and optimally stretched pulses. A remarkably simple double-pulse structure, containing a low-intensity prepulse and a stronger main pulse, turns out to produce the highest atomic charge states up to Ag${}^{20+}$. A negative chirp during the main pulse hints at dynamic frequency locking to the cluster plasmon. A numerical optimal control study on pure silver clusters with a nanoplasma model converges to a similar pulse structure and corroborates, that the optimal light field adapts to the resonant excitation of cluster surface plasmons for efficient ionization.

7 pages, 5 figures, text revised

References in corpus (4)

• Ionization of clusters in intense laser pulses through collective electron dynamics
• Energy absorption of xenon clusters in helium nanodroplets under strong laser pulses
• Optimizing the ionization and energy absorption of laser-irradiated clusters
• Laser-Cluster-Interaction in a Nanoplasma-Model with Inclusion of Lowered Ionization Energies

Cited by in corpus (4)

• Laser-driven nonlinear cluster dynamics
• Electrons as probes of dynamics in molecules and clusters : a contribution from Time Dependent Density Functional Theory
• Resonant charging of Xe clusters in Helium nanodroplets under intense laser fields
• Exploring the complexity of quantum control optimization trajectories