Synthetic dimensions in integrated photonics: From optical isolation to 4D quantum Hall physics

Tomoki Ozawa, Hannah M. Price, Nathan Goldman, Oded Zilberberg, Iacopo Carusotto

Published 2015-10-13Version 1

Recent technological advances in integrated photonics have spurred on the study of topological phenomena in engineered bosonic systems. Indeed, the controllability of silicon ring-resonator arrays has opened up new perspectives for building lattices for photons with topologically non-trivial bands and integrating them into photonic devices for practical applications. Here, we push these ideas even further by exploiting the different modes of a silicon ring-resonator as an extra dimension for photons. Tunneling along this "synthetic" dimension is implemented via an external time-dependent modulation that allows for the generation of engineered gauge fields. We present how this approach can be used to generate a variety of exciting topological phenomena in integrated photonics, ranging from (i) a topologically-robust optical isolator in a spatially 1D ring-resonator chain to (ii) a driven-dissipative analogue of the 4D quantum Hall effect in a spatially 3D resonator lattice. Our proposal paves the way towards the use of topological effects in the design of novel photonic lattices supporting many frequency channels and displaying higher connectivities.