Integrating Brillouin processing with functional circuits for enhanced RF photonic processing

On-chip linear and nonlinear optical effects have shown tremendous potentials for applications in RF photonic signal processing. Combining their complementary optical properties in the same integrated platform is expected to satisfy the future increasing demands of high-performance integrated microwave photonic systems. However, the integration of linear circuits with high-performance optical nonlinearity elements remains challenging. Here, we report the first proof-of-concept demonstration of a microwave photonic notch filter based on the simultaneous integration of active Brillouin circuits and passive ring resonators on the same photonic chip, merging advanced filtering functionality, optimized performance and compactness.