A team of scientists from the Faculty of Sciences of the University of Porto (FCUP) has developed and built a new ultrafast laser system for the production and observation of magnetic processes at an unprecedented time scale of less than 10 femtoseconds (1 femtosecond = 0.000,000,000,000,001 seconds), setting a new worldwide limit for the speed at which one can modify the magnetization of materials directly with laser light. The new system and the results obtained should have an impact on the development of new magneto-optical materials and technologies, for applications in biomedical sensors and for high-speed recording and reading of information, and have earned a publication in the prestigious journal Scientific Reports, an open-access publication from the Nature group.
Helder Crespo, professor at the University of Porto, and David Schmool, former professor at the University of Porto, currently research director at CNRS (Centre National de la Recherche Scientifique, France) and professor at the University of Versailles, led the team of scientists from the Physics and Astronomy Department at FCUP (Ultrafast Lasers and Magnetodynamic Spectroscopies Group from IFIMUP-IN - Institute of Materials Physics from the University of Porto), which reached these results from a strategic scientific planning, which included three projects supported by FCT.
In Helder Crespo's opinion, "FCT's support was crucial to the development of all scientific activity, from the acquisition of components and instruments to build the various systems, to advanced training of human resources," with five doctoral theses developed in the scope of these projects.
These advances are directly related to a new technology for compression and measurement of ultra-short laser pulses, called dispersion-scan (or d-scan), invented and patented at the University of Porto in collaboration with the University of Lund. This revolutionary technique is also the basis of a new high-tech company based in Porto, Sphere Ultrafast Photonics (spin-off from the University of Porto), which manufactures and distributes this unique technology in the world scientific market.
Today it is possible to store large amounts of information on digital magnetic media, which has to be accompanied by a corresponding increase in writing and reading speed. Otherwise, the system in question becomes slow relative to its capacity. The study and understanding of the fundamental phenomena behind magnetism is a very important challenge in this cutting-edge technology, where we are trying to find out how fast and how fast we can read and write bits on a magnetic material.