Narrowband microwave-photonic notch filters using Brillouin-based signal transduction in silicon

The growing demand for bandwidth makes photonic systems a leading candidate for future telecommunication and radar technologies. Integrated photonic systems offer ultra-wideband performance within a small footprint, which can naturally interface with fiber-optic networks for signal transmission. However, it remains challenging to realize narrowband (similar to MHz) filters needed for high-performance communications systems using integrated photonics. In this paper, we demonstrate all-silicon microwave-photonic notch filters with 50x higher spectral resolution than previously realized in silicon photonics. This enhanced performance is achieved by utilizing optomechanical interactions to access long-lived phonons, greatly extending available coherence times in silicon. We use a multi-port Brillouin-based optomechanical system to demonstrate ultra-narrowband (2.7 MHz) notch filters with high rejection (57 dB) and frequency tunability over a wide spectral band (6 GHz) within a microwave-photonic link. We accomplish this with an all-silicon waveguide system, using CMOS-compatible fabrication techniques. It remains challenging to realize narrowband filters needed for high-performance communications systems using integrated photonics. Using a multi-port Brillouin-based optomechanical system, the authors demonstrate an ultra-narrowband notch filter with high rejection with CMOS compatible techniques.

Automated summary

The growing demand for bandwidth has made photonic systems a leading candidate for future telecommunication and radar technologies. However, it remains challenging to realize narrowband filters needed for high-performance communications systems using integrated photonics. In this study, the authors demonstrate all-silicon microwave-photonic notch filters with significantly higher spectral resolution by utilizing optomechanical interactions to access long-lived phonons in silicon.