His most recent and most successful research is that into the manipulation of magnetism using light. In a computer hard disk, information is stored by setting the magnetic direction of individual magnetic domains either 'up' or 'down' by applying a magnetic field either parallel or antiparallel to the magnetisation direction. Rasing developed a method to change the magnetic areas using very short laser pulses that switch their polarisation rapidly. This might eventually allow information to be recorded up to 100,000 times faster than is currently possible.

Previously, the physicist played a prominent role in the development of a new method which used lasers to visualise the movement of molecules over a surface, a technique now widely used. Furthermore, his study of extremely thin magnetic layers led to the discovery of new large magneto-optical effects, which can be used to study magnetism at interfaces and on nanostructures.

Theo Rasing frequently gives public lectures and is not afraid to enter into public debate about the pros and cons of technology. He has a large research group and knows how to attract considerable funding for this. For his researchers he is an inspiring leader who gives a lot of care and attention to each individual. His active supervision of students during the preparation of articles or lectures has led to them winning prizes on many occasions. His enthusiasm, broad scientific knowledge, international fame, inspiring personality and leadership give the Spinoza Committee every confidence that Rasing will invest the Spinoza Prize very wisely.

This jury report served as the basis for the speech given by Prof. Hans Mooij at the announcement ceremony for the NWO/Spinoza prizes 2008 on 2 June 2008.