Image: László Veisz
Research project The interaction of high-intensity, few optical-cycle long laser pulses with nanometer-sized objects offers a mean to emit and accelerate a bunch of electrons to almost the speed of the light with a unique duration in the attosecond regime. This fundamentally new source of electron pulses as short flashes in photography will open the way for novel time-resolved filming of electron dynamics in matter and the next-level temporal metrology.
The project is financed by the Swedish Research Council. The grant is an environment grant.
University of Gothenburg :
Responsible researcher: Dag Hanstorp
PhD Student: Javier Marmolejo
University of Gothenburg :
Responsible researcher: Mattias Marklund
Assistant Professor: Arkady Gonoskov
Assistant Professor: Thomas Blackburn
Postdoc: Julien Ferri
Postdoc: Shikha Bhadoria
Laser light, where all photons move in unison and without spreading significantly, has provided a scientific and technical revolution. Everything from CD and DVD readers, medical applications and welding to basic experiments in atomic and molecular physics have been made possible via the laser's unique properties. Since the mid-1980s, the available laser intensity has increased every year via a new technology for which Gerard Mourou and Donna Strickland were awarded one half of the Nobel Prize in Physics 2018. Now the power of a single laser pulse can amount to one million billion watts. If this power is focused on a micrometer-sized surface, the intensity becomes enormous. These amazing laser properties can already be used to accelerate short electron pulses, and these electrons can be applied to film molecular and atomic processes. The electrons reach speeds close to the speed of light at such acceleration, and also inherit properties from both the laser pulse and the electron source, normally a gas. Today's technology, however, has limitations, as it is not possible to make as short electron pulses as laser pulses. This limits the possibility of carrying out extreme measurements, such as photographing the dynamics of the electrons in an atom. Therefore, there is also a great interest in finding new methods for realizing these ultra-short electron pulses, to provide the opportunity to study new phenomena in chemistry, biology, and medicine as well as basic physics.
To achieve this, a unique collaboration between experiment and theory is required, something that will be realized within this project. In this project we will illuminate a microscopic object with an extremely short and strong laser pulse. To avoid interaction with the particle's sample holder, which would greatly affect our results, we will instead levitate the obejct in a so-called optical trap which consists of a (second) focused laser beam. In this trap, a particle in the vicinity of the beam is drawn to the most intense part of the laser beam where it will be captured and remain as long as the laser light is on. Using this method without touching the object, we can hold it inside a vacuum chamber and thereby carry out experiments, where we study the interaction between the intense laser pulse and the nano object. The second half of the 2018 Nobel Prize in Physics was awarded to Arthur Ashkin for developing the method of trapping particles using light.
With the help of optical levitation, uniquely short high-power laser pulses and groundbreaking simulations, we will in this project try to find ways to achieve the shortest electron and light pulses ever created in a laboratory. The goals that the research is focused on will have a significant influence on a wide range of areas, such as quantum mechanical electron processes in atoms, light-driven fast electronics, biological structure determination and extreme time-resolved measurements.
