On-chip frequency space lattices in modulated thin-film lithium niobate microresonators

We use thin-film lithium niobate integrated electro-optically modulated ring cavities for modelling frequency dimension tight-binding lattices with configurable lattice connectivity. This is achieved by driving broadband travelling-wave modulator sections using a set of free-spectral range matching radio frequency signals. Inter-mode coupling range, rate, and hopping phase can be directly tuned via the modulating radio frequency signals. Furthermore, ring cavity mode engineering concepts are explored to disrupt their typically equidistant spacing, to either induce boundaries along the frequency space, or to create sets of frequency-staggered modes for non-trivial lattice realization. Acquisition of band structures and spectral characterization for each system provide a direct way for probing the modelled behavior.