ATTOCO

Attosecond Coherent Control

 Partecipanti

Mappa

 Word cloud

Esplora la "nuvola delle parole (Word Cloud) per avere un'idea di massima del progetto.

 Obiettivo del progetto (Objective)

'During the last decade, the advent of reliable lasers capable of producing pulses of light with duration of merely a few femtoseconds brought on a revolution not only in laser physics but in many other fields of science as well. The next step is to controllably produce pulses with duration in the attosecond regime. Attosecond technology is expected to lead to numerous applications in atomic and molecular physics and in material and surface science. The goal of this project is to improve the control of attosecond pulse generation, and to use this improved control to study coherent control of ionization dynamics in gases. In order to do this, an upgrade to the existing laser setup at Lund University is needed. Therefore, the first objective is to install a new state-of-the-art laser system for the production of attosecond pulses. The second objective is to use the new system to produce stable attosecond pulse trains where the number of pulses in the trains can be varied from about ten down to a single isolated pulse. Such control is beyond that what is currently available anywhere and is unique to this work. Very recently, using attosecond pulse trains centred below the ionization threshold of helium atoms, the Lund group observed a strong modulation of the ionization signal on an attosecond time scale. The depth of modulation depended on the separation between the attosecond pulses as well as on the number of the pulses in the pulse train. In the third objective of this proposal, the newly added control of the pulse trains will be used to study this very recent development further. The vision is to enable control of a broad range of ionization, excitation and dissociation processes in atoms, molecules and more complex systems by directly affecting the electronic motion on its attosecond time scale.'

Introduzione (Teaser)

Flashing lasers at a quintillionth of a second are taking laser science to new heights. The fields of atomic physics and molecular physics stand to gain considerably from these advances.

Descrizione progetto (Article)

Lasers can produce pulses of light that have a variety of uses in science and technology. The quicker the pulse, the more potential for novel and better applications in research laboratories, with a variety of new ideas that will advance the cause of science.

In recent years science created lasers that produce pulses in the femtosecond range (one quadrillionth of a second). The next frontier is to produce pulses in the attosecond range (one quintillionth of a second). Attosecond technology can lead to numerous applications in atomic and molecular physics, as well as in material and surface science.

The EU-funded project 'Attosecond Coherent Control' (Attoco) worked on overseeing the generation of attosecond pulses. It started by upgrading current laser facilities at Lund University in Sweden, installing a new state-of-the-art laser system to produce these attosecond pulses. This allowed the team to create stable attosecond pulses, with the number of pulses in trains that are capable of being varied roughly between 1 and 10 isolated pulses.

This heralded a new level of laser control that opens up a world of possibilities. The team even recorded strong modulation of the ionisation signal on an attosecond time scale using attosecond pulse trains that were centred below the ionisation threshold of helium atoms.

In addition, this precision of pulse trains was exploited in further experiments to control a variety of ionisation, excitation and dissociation processes in atoms, molecules and more complex systems. All this can be realised by directly altering the electronic motion of these minute bodies on the attosecond time scale.

In the upgraded laboratory the team worked on vacuum technology, specialised high-level instrumentation, temporal gating, ultrashort pulse measurements using different devices, laser beam pointing and pulse energy stabilisation.

These topics will help to advance the applications of attosecond laser pulses with a myriad of surprising results expected in the next few years.