Phys.org October 10, 2022
The filtering, amplifying, and processing of optical signals is essential in the development of new telecommunication techniques, quantum optics and sensors. One pathway to do this effectively is by using Brillouin scattering. However, Brillouin scattering (SBS) in the emerging silicon nitride (Si3N4) photonic integration platform is currently out of reach because of the lack of acoustic guidance. An international team of researchers (the Netherlands, Switzerland) demonstrated advanced control of backward SBS in multilayer Si3N4 waveguides. By optimizing the separation between two Si3N4 layers, they unlocked acoustic waveguiding in this platform, potentially leading up to 15× higher Brillouin gain coefficient than previously possible in Si3N4 waveguides. They used the enhanced SBS gain to demonstrate a high-rejection microwave photonic notch filter. According to the researchers their work opens a path to achieving Brillouin-based photonic circuits in a standard, low-loss Si3N4 platform…read more. Open Access TECHNICAL ARTICLEÂ
Guided-acoustic Brillouin scattering in multilayer silicon nitride waveguides….Credit: Science Advances, Vol 8, Issue 40, 7 Oct 2022Â