From Photons to Radiation
The group activities span from studies of interactions between light and matter in macroscopic systems to quantum mechanical processes at nano-size or at the atomic level. They encompass both experimental and theoretical projects and we cooperate with a large number of researchers, research groups and organizations in Norway and abroad. A professor of physics didactics responsible for the physics education teaching at the University of Bergen is also associated with the group.
This picture exhibits some of the group members, anno 2012 (Photo I. Heggstad)
Physics education, Quantum mechanics, Quantum information, Atoms in Strong fields and Collisions, Rydberg atoms, Radiation, Light and Life, Algea, Climate physics, Remote sensing...
Guests and students 2014: Sondre Eliasson, Lars Håvik, Jørgen Rørstad (MSc students), Silvina Pugliese (guest researcher, Bariloche, Argentina January-June), Daniel Fregenal, guest researcher, Bariloche, Argentina, May-June), Martin Kozak (guest researcher, Prague, June-July), Nuozheng Gelsor, Punam Sharma (MSc students).
Some ongoing research projects:
The light penetrating the sea ice is important both for life under the sea ice and for warming the Arctic. The group collaborate with the Norwegian Polar Institute and Stevens Institute of Technology to acquire more knowledge about on how the transmission of sunlight varies with position and time in the Arctic, with a particular focus on primary and secondary ice, which now dominate large areas. We combine in situ measurements of light and optical properties of snow, ice and water with numerical modeling to determine how the natural variations of snow, ice thickness, salinity and air content, plankton concentration, etc. affect the spectrum below the ice. The goal is to use this information, for example, to determine how changes in ice conditions affect the total primary production and energy deposition in the Arctic.
Graphene is a thin material with unique strength and characteristics. It consists of a single layer of carbon atoms linked together in a honeycomb lattice of molecular bondings. The group studies how the material responds to strong short interactions set up by the passing ions or laser pulses. More info: High-order harmonic generation in graphene flakes exposed tocircularly polarized femtosecond pulses. Rydberg Atoms - are atoms with electron in highly excited quantum states. These are characterized by long lifetime and high sensitivity to electromagnetic fields that allow atomic quantum states to be manipulated in the laboratory. The group works with a number Rydberg phenomena such Rydberg molecules, responses to multiple laser pulses, and quantum information. More info: S. I. Simonsen, J. P. Hansen and L. Kocbach, Labtalk IOP, 2012 . Quantum dots, rings and molecules - are two-dimensional nanostructures with discrete energy levels and can be produced with controlled properties on surfaces. We study their characteristics and responses to electromagnetic fields. More info: Two-electron quantum dot in tilted magnetic fields: Sensitivity of the confinement model
Measurement and imaging of fluorescence lifetime: The fluorescence lifetime is the average time an atom or molecule is excited before it emits fluorescence. The lifetime is independent of the concentration of the fluorescent molecules, thereby providing information beyond intensity measurements. A femtosecond laser used as a light source, and the pulses focused through a laser scanning microscope so that two-photon excitation can be achieved. Currently we measure the fluorescence lifetime of chlorophyll in algae, where we gradually expose the algae to UV radiation and observe how this changes the life. This will hopefully provide more insight into both the photosynthetic processes and the various mechanisms that are implemented in cells to protect against damaging light. Imaging of fluorescence lifetime provides a visual insight to how the cells change occurs.
Physics Didactics: Many students learn less in the natural sciences than desirable, which may limit their opportunities for participation in social debates and professional life. In our work in science education, we investigate how the experiment based exploratory workings and dialogue in education can promote academic participation and understanding. Based on our previous studies of the conditions for reflective decision making in social and consumer issues where science arguments are included, we explore didactic models where such issues are used as pivot points for teaching.