Controlling the reflection and emission of light via photonic crystals and quasicrystals

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 of finding 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.

More specifically on the reflectivity, we extract the bands of 2D photonic crystals in the plane of periodicity, find new and exciting properties of 2D photonic quasicrystals, study a backward propagating surface defect wave on a 3D photonic band gap crystal, and observe a band-gap-like reflectivity on a 3D photonic crystal outside the band gap. For emission, we calculate the radiative local density of states to model decay curves of quantum emitters in photonic crystals, and study spontaneous emission in 3D photonic band gap crystals. Overall, our results form an up-to-date basis for the control of light by photonic crystals and quasicrystals.