Chips and electronic devices have become exponentially smaller and faster in recent decades. We have nearly reached the limits of ‘traditional’ electronics and are now transitioning from electronics to photonics, which uses light instead of electrons. Scientists have developed a new technique for trapping sound waves and light using multilayer silicon nitride waveguides. The project successfully demonstrated that manipulating light with sound in large-scale circuits is feasible and compatible with current manufacturing methods.
Filtering, amplifying, and processing optical signals are critical in developing new telecommunications, quantum optics, and sensors. One effective method is to use a coherent optomechanical interaction technique known as stimulated Brillouin scattering. In this technique, two finely tuned lasers generate a soundwave with frequencies one million times higher than the human hearing threshold and trap it in a waveguide. Light passing through the waveguide interacts with the soundwave, reflecting a very small and specific portion of the light spectrum and thus filtering the signal.
The silicon nitride waveguide study enables the integration of stimulated Brillouin scattering in large circuits. These new chips can be combined with other emerging technologies like tunable lasers, frequency combs, and programmable photonic circuits, potentially allowing them to play a role in the future development of fields like telecommunications and quantum computing.