Suppression of Parasitic Nonlinear Processes in Spontaneous Four-Wave Mixing with Linearly Uncoupled Resonators

Phys Rev Lett. 2021 Jul 16;127(3):033901. doi: 10.1103/PhysRevLett.127.033901.

Abstract

We report on a signal-to-noise ratio characterizing the generation of identical photon pairs of more than 4 orders of magnitude in a ring resonator system. Parasitic noise, associated with single-pump spontaneous four-wave mixing, is essentially eliminated by employing a novel system design involving two resonators that are linearly uncoupled but nonlinearly coupled. This opens the way to a new class of integrated devices exploiting the unique properties of identical photon pairs in the same optical mode.