Photonic Simulations and Quantum Interference in Laser-Written Waveguide Arrays

by Ang Chen (Stockholm University)

Tuesday 3 Jun 2025, 15:00 → 16:00 Europe/Stockholm

AlbaNova C4:3031 (AlbaNova Main Building)

Over the past two decades, photonic platforms have emerged as powerful tools for simulating and exploring a broad range of physical phenomena. Among these, femtosecond laser-written waveguide arrays offer a flexible and accessible architecture for investigating effects from both condensed matter physics and quantum optics.
This work reviews the key concepts and mechanisms of photonic simulations that can be described by tight-binding models. The laser writing technique enables precise control over hopping amplitudes and facilitates the implementation of non-Hermitian and Floquet engineering in waveguide systems. In particular, we study two-dimensional localization through several mechanisms and experimentally demonstrate flat-band localization in a diamond lattice.
In the quantum regime, we perform linear optical experiments using single photons generated via spontaneous parametric down-conversion (SPDC). By injecting indistinguishable photons into engineered lattices, we observe high-visibility Hong–Ou–Mandel (HOM) dips, which indicates quantum interference. We also propose future experiments investigating quantum interference between compact localized states (CLSs) in specially designed structures.