Einstein’s theory of general relativity has dramatically changed our world view, by describing gravity as an intrinsic deformation of space and time. About fifteen years ago, John Pendry and Ulf Leonhard had the intriguing idea to emulate the behaviour of light in a deformed space by making use of carefully designed artificial metamaterials. Metamaterials consist of elements that are very small with respect to the characteristic length of light waves. By optimizing the shape, the density, and the size of these elements, metamaterials can control light rays in a very precise way.
A priori, it is very difficult, if not impossible, to determine what metamaterial properties impose a desired bend, split, or concentration of light rays. Transformation optics is a geometrical technique that allows determining what metamaterial properties reproduce the light path inside a deformed space. This has resulted in impressive and, at the same time, intuitive, material designs such as invisibility devices that hide an object by guiding light rays around it.
Thanks to rapidly advancing fabrication methods, metamaterial designs may result in a variety of novel properties, such as reconfigurable, two-dimensional, or quantum properties. In the first part of her thesis, Sophie introduces new concepts to describe reconfigurable metamaterials with properties that are controlled by an external signal. For example, she has developed a consistent description of materials that implement vector potentials for photons to enhance optical forces, and she has discovered that reconfigurable metamaterials are subject to a fundamental speed limit. These findings are important because they point out that active photonic switches can only be improved up to a certain point by making use of metamaterial structures. In the second part of her thesis, Sophie extends the geometrical tools of transformation optics to improve on the understanding of two-dimensional metamaterials and quantum metamaterials. This has allowed designing metamaterial layers that guide light along their surface and has provided new insights into the behaviour of light sources inside metamaterial black holes, which impose a gravitational wave vector shift.
By describing advanced electromagnetic phenomena inside reconfigurable, two-dimensional, and quantum metamaterials in an intuitive way, this thesis has contributed to advanced material designs that may be useful in future light-based applications.
Congratulations Sophie! We are proud supervisors.
The campaign “A question for Science” is an initiative of the Flanders Scientific Research Fund (FWO), commissioned by Flemish Minister Muyters, responsible for science and innovation, in collaboration with a broad group of scientific organizations, such as the Flemish universities and colleges, the KVAB, the Young Academy, the strategic research centers …
As an ambassadors of this initiative, I have answered one of the questions that was submitted to the website. The answer was published in the Belgian newspaper Het Nieuwsblad.
The full article can be found here.
Opinion piece in Belgian newspaper De Morgen.
Science is a story of many punctuation marks. The facts (!) the context (,) the nuance (;) but also the questions (?). In this article, we highlight about the importance of those question marks.
Full article can be read here.
Ultrathin nanostructured resonators on surfaces, i.e., metasurfaces, have shown great potential for the miniaturization of advanced photonic technologies such as aberration-free lenses, beam shapers, and holograms. These metasurface designs focus strongly on obtaining desired optical properties through a careful optimization of the shape, the relative orientation, and the composition of structures. However, once manufactured the resulting optimized properties cannot change, preventing the use of metasurfaces in the implementation of displays or wearables, needed for applications involving augmented and virtual reality.
Plenary lecture at the Earth, Space and Science, organized by the National Committee of Chemistry together with the Jeunesses Scientifiques, les Olympiades. Presenting my ideas on the future of Science and Education to more than 220 young students.
Volunteering at the Cambridge Science Fest, explaining the surprising science behind color together with the Harvard SEAS Photonics Club. Some exciting demos, including:
1: What is color?
2: What is light?
3: How are colors formed in nature?
4: How do I make colors like a peacock?
Opinion piece by the Young Academy in the Belgian newspaper De Standaard on the occasion of the 2018 March for Science.
A plea to invest more in science and education. It is the only way to create a society based on critical thinking.
The full article can be found here.