18 February 2016

Pioneer in the field of ‘wavefront shaping’ Allard Mosk Professor of Physics of Light in Complex Systems

 

As of November 2015, Allard Mosk was appointed as Professor of Physics of Light in Complex Systems at the Debye Institute for Nanomaterials at Utrecht University. In December, he and his research group moved from the University of Twente to the Ornstein Laboratory at the Uithof. Mosk is considered to be an international pioneer in the field of wavefront shaping, in which light is manipulated in such a way as to ‘see’ through opaque materials. Three years ago, his research resulted in a publication in Nature, which was mentioned in international media. In early 2015, Mosk received a Vici (Advanced career) grant for his research proposal in the field.

Mosk explains that he enjoyed working at the University of Twente for 13 years. “But here in Utrecht I had the opportunity to set up a new chair group with a tenure tracker in an environment where there are good ties to chemists, biophysicists and theoretical physicists. Plus, Utrecht’s location in the middle of the country ensures a good flow of excellent students.”

Understanding

Although Mosk enjoys the collaboration with businesses and applying his research, his main motivation is to understand the phenomenon of dispersion. “It has only been a few years since we were first able to study and control light at the nano scale, a dimension much smaller than the wavelength of light. I want to understand the principles of scattering of light and electrons at this scale. With our experiments, we develop and test the theories in this field using light, because light is easier to detect than other waves.”

Opaque materials

Studying scattering is essential in order to see through opaque materials, such paper and skin. The trick is to steer the incoming light in such a way to compensate for the scattering by the material. To do this, researchers shine laser light through an opaque material and a camera registers how it is scattered. Using learning algorithms, after millions of measurements it is possible to manipulate the incoming light in such a way that the light waves produce a clear image of what is behind the material.

Businesses

“If we can do this successfully with paper, then in principle we should be able to look through all scattering materials that are not too thick and absorbent”, explains Mosk. A number of businesses are therefore very interested in his research. Mosk works together with ASML, for example, because the company sees possible applications in the computer chip industry. Another interesting application is in medical imaging techniques for looking through skin. The technique may also enable microscopic measurements with a much higher resolution that a light microscope, but without the limitations of an electron microscope.

Students

The best thing is, as Mosk explains, the equipment used is not extremely complicated. “Good students can learn how to use the equipment in just a few weeks, and start to get results. And they’ve even worked on experiments that have led the way in the optics of dispersive systems.” Mosk taught both undergraduate and graduate courses in Twente, and will continue to do so in Utrecht.

Fellow of the Optical Society

Allard Mosk (1970) studied Theoretical Physics and earned his PhD. there on the subject of experimental research. After that, he did a postdoc at the Max-Planck-Institut für Kernphysik in Heidelberg and was a visiting professor at the Ecole Normale Supérieure in Paris. He has been affiliated with the University of Twente since 2003, where he was appointed as Professor in 2014. After a Vidi grant in 2007, he received an ERC Consolidator Grant in 2011 and a Vici grant in 2015. In 2015, he was also named a Fellow of the international Optical Society (OSA).