Linearized Integrated Microwave Photonic Circuit for Filtering and Phase Shifting

Abstract

Photonic integration, advanced functionality, reconfigurability, and high RF performance are key features in integrated microwave photonic systems that are still difficult to achieve simultaneously. In this work, we demonstrate an integrated microwave photonic circuit that can be reconfigured for two distinct RF functions, namely, a tunable notch filter and a phase shifter. We achieved $>$50dB high-extinction notch filtering over 6-16 GHz and 2$\pi$ continuously tunable phase shifting over 12-20 GHz frequencies. At the same time, we implemented an on-chip linearization technique to achieve a spurious-free dynamic range of more than 120$\rm{dB}\cdot \rm{Hz}^{4/5}$ for both functions. Our work combines multi-functionality and linearization in one photonic integrated circuit, and paves the way to reconfigurable RF photonic front-ends with very high performance.