Synthetic dimension band structures on a Si CMOS photonic platform

TL;DR

This paper demonstrates the first silicon CMOS photonic device implementing a synthetic frequency dimension, enabling the simulation of higher-dimensional topological phenomena through coupled mode lattices and gauge potentials.

Contribution

It introduces a CMOS-fabricated silicon ring resonator that realizes a synthetic frequency dimension and demonstrates control over gauge potentials affecting band structures.

Findings

Achieved up to 280 GHz optical spectra

Measured synthetic band structures on-chip

Realized gauge potentials affecting band topology

Abstract

Synthetic dimensions, which simulate spatial coordinates using non-spatial degrees of freedom, are drawing interest in topological science and other fields for modelling higher-dimensional phenomena on simple structures. We present the first realization of a synthetic frequency dimension on a silicon ring resonator photonic device fabricated using a CMOS process. We confirm that its coupled modes correspond to a 1D tight-binding model through acquisition of up to 280 GHz bandwidth optical frequency comb-like spectra, and by measuring the first synthetic band structures on an integrated device. Furthermore, we realized two types of gauge potentials along the frequency dimension, and probed their effects through the associated band structures. An electric field analogue was produced via modulation detuning, whereas effective magnetic fields were induced using synchronized nearest- and second-nearest-neighbor coupling. Creation of coupled mode lattices and two effective forces on a monolithic Si CMOS device represents a key step towards wider adoption of topological principles.