Research

Our research is focused on exploring fundamental concepts in nanophotonics and pushing technological and scientific boundaries.

Slow light and disorder

Scanning electron microscope image of a photonic crystal slow light waveguide.

Nanophotonic devices offer the unique ability to control the spatial and temporal properties of light by modifying the device structure. One aspect of this is a reduction of the group velocity of light, leading to enhanced light-matter interactions and reduced device footprints.

We focus on the development of photonic crystal devices for ultra-slow light with low propagation losses and on understanding and utilizing the impact of disorder in nanophotonics.

 

Nonlinear optics, metasurfaces and epsilon-near-zero materials

 

Schematic of a metasurface for nonlinear optical applications.

Metasurfaces are artificial thin films or two-dimensional materials, with designer optical properties. They are the ideal platform to manipulate optical beams. For example, we can create structured light or flat optical elements using metasurfaces.

We are interested in metasurfaces with a custom engineered nonlinear optical response. We achieve this by coupling metasurfaces to thin films of epsilon-near-zero materials. In epsilon-near-zero materials, the electric permittivity crosses through zero. In the vicinity of this zero-crossing, the material can exhibit unusual optical properties.

We have demonstrated that a metasurfaces incorporating an epsilon-near-zero film has an ultra-strong nonlinear optical response.

Non-reciprocal photonics

In non-reciprocal systems the propagation of light is no longer symmetric in space and time. The best-known example of a non-reciprocal system is the Faraday isolator.

We work on the implementation of non-reciprocity in nanophotonic systems and study the fundamental differences between reciprocal and non-reciprocal systems. For example, some seemingly fundamental relations, such as the time-bandwidth product, are no longer universal to all non-reciprocal systems

Schematic of a propoosed non-reciprocal waveguide with a reflective metal termination. This proposed sytem can overcome the traditional time-bandwidth limit by three orders of magnitude.