Observation of a Brillouin dynamic grating in silicon nitride waveguides

TL;DR

This paper reports the first observation of a Brillouin dynamic grating in silicon nitride waveguides, demonstrating its potential for tunable optical filtering in integrated microwave photonics circuits.

Contribution

It presents the first experimental demonstration of BDG in silicon nitride waveguides and introduces an optimized design to enhance its response for large-scale integration.

Findings

First observation of BDG in Si3N4 waveguides

Optimized waveguide design enhances BDG response

Potential for integration into large-scale MWP circuits

Abstract

Brillouin enhanced four wave mixing in the form of a Brillouin dynamic grating (BDG) enables a uniquely tunable filter, whose properties can be tuned by purely optical means. This makes the BDG a valuable tool in microwave photonics (MWP). BDGs have been studied extensively in fibers, but the only observation in an integrated platform required exotic materials. Unlocking BDG in a standard and mature platform will enable its integration into large-scale circuits. Here we demonstrate the first observation of a BDG in a silicon nitride (Si$_3$N$_4$) waveguide. We also present a new, optimized design, which will enhance the BDG response of the waveguide, unlocking a path to large-scale integration into MWP circuits.