PhD Defence Timon Vreman | Controlling the Reflection and Emission of Light via Photonic Crystals and Quasicrystals

Controlling the Reflection and Emission of Light via Photonic Crystals and Quasicrystals

Timon Vreman is a PhD student in the department Complex Photonic Systems. (Co)Promotors are prof.dr. W.L. Vos and prof.dr. A. Lagendijk from the faculty Science & Technology (TNW), University of Twente.

Light is essential for most forms of life on our planet. It has interesting properties: Our hands can move objects like stones, but light cannot just be grabbed and placed somewhere else. Instead, to get light at a particular spot, you need to steer it in that direction (e.g., via reflection) or produce it at that spot (i.e., via emission).

Photonic crystals and quasicrystals are periodic and quasiperiodic structures designed to control light. To achieve this control, they exploit the wave nature of light, namely by using constructive and destructive interference. Possibly counterintuitively, despite being made from transparent materials, the control of light that these structures offer is very strong.

 In this PhD thesis, I explore the control of light by photonic crystals and quasicrystals in an experimental setting with the goal to find new ways to control light. We manufacture the photonic crystals and quasicrystals ourselves using silicon lithography. To study their optical properties, we develop and modernize complex optical setups. These include custom-built angle-resolved reflection and time-resolved emission setups upgraded using new objectives and detectors. Our reflectivity and emission setups provide large datasets with detailed information about how light interacts with these photonic structures. Every experimental chapter compares experimental data with theoretical calculations and numerical simulations computed using open-source simulation packages. The agreement between experiment and theory is often excellent, and from the discrepancies, we learn about the differences between theoretical and experimental nanostructures. Our results form an up-to-date basis for the control of light by photonic crystals and quasicrystals.

You are welcome to join the public PhD defense of my thesis in person or online via the link above. The full thesis will be available online soon on the website of our research group at nano-cops.com/publications/phd/.