Topological Photonic Lattices

Abstract: Topological Photonics is a rapidly growing field which explores the ideas of topological invariants adapted from condensed matter physics to optical systems. Thanks to integrated photonics platforms, the evolution of light in nanoscale photonic lattices can enable direct measurement of topological properties of the band-structure. In this degree project, we study the topological Anderson phase transition in disordered one-dimensional lattices, and probe distinct topological phases in photonic superlattices. In first part, we fabricate photonic lattices with different disorder strength, and observe the topological transition from trivial topological Anderson phase to non-trivial topological Anderson phase as the system disorder is increased. In second part, we focus on probing the Zak phase in photonic superlattices. We fabricate a superlattice system that utilizes either bulk excitation or edge excitation. We identify the trivial and non-trivial Zak phase using two methods: first, through reconstructing the intensity evolution in the edge waveguide, second, through calculating the beam displacement in the case of bulk excitation .  In order to study the evolution of the light in the nano-scaled photonic lattices, we develop a novel technique: Loss-Induced Scattering Approach (LISA), which enables high fidelity reconstruction of the photonic state evolving in the lattice.