Photonic topological insulator laser using III-V semiconductor nanowires

A topological insulator is an extraordinary material - it acts as an electrical bulk insulator that allows an electrical current flow along its surface.

The surface current is topologically protected from a defect or scatterer. In analogy, a photonic topological insulator has no bulk mode but allows for edge modes at the interfaces with other types of photonic topological materials. The edge mode in photonic topological insulators is very promising for applications since it provides a practical way of one-way propagation that could significantly reduce propagation losses.

In this project, we aim to develop a new type of semiconductor laser with exceptional directionality and a one-way waveguide with extremely low loss using the edge modes of photonic topological insulators. For this, we investigate topologically protected edge modes of a semiconductor nanowire array and explore the dynamics of electrons and photons in the edge mode laser.

For experimental demonstration, edge mode lasers and one-way waveguides will be fabricated using a III-V semiconductor nanowire array grown on top of a silicon-on-insulator wafer and characterised with electrical and optical pumping.

The project is led by Dr Sang Soon Oh who joined the Institute of Compound Semiconductors as a recipient of Rising Star Fellowship supported by the Welsh government. He has an expertise in metamaterials, plasmonics, semiconductor lasers and topological photonics.