Extracting the Berry Phase of Dimer Chains in a Synthetic Dimension

Thanks to their versatility, photonic systems have proven to be particularly advantageous for emulating and exploring topological phases of matter, often beyond what is physically reachable in the solid-state ¹ . Recent efforts to couple internal degrees of freedom of the electromagnetic field, rather than spatial modes, have led to the emulation of topological materials in synthetic dimensions. One important example is provided by optical fiber loops whose cavity eigenmodes are coupled with a phase modulator driven at the frequency of the free spectral range (FSR) ² . Such an approach has allowed exploring non-hermitian band structures ³ and two-dimensional materials with twisted boundary conditions ⁴ .