Link Performance Optimization of Chip-Based Si3N4 Microwave Photonic Filters

Simultaneously achieving high link performance and advanced microwave photonic processing functionalities in compact integrated circuits is crucial but challenging for the deployment in future and existing practical applications. In this paper, we present the first comprehensive experimental study to optimize the link performance of a Si3N4-photonic-chip-based microwave photonic notch filter. This systematic study leads to an optimized link performance of the chip-based filter, demonstrating an RF net gain, a sub-20-dB noise figure and an overall third-order spurious-free dynamic range of 115 dB.Hz(2/3) over a frequency range of 0-12 GHz, in conjunction with advanced filtering functionalities with a notch rejection >50 dB. The achieved performance is based on a unique and low-loss chip-based filter scheme which offers the compatibility with existing link performance optimization techniques, while maintaining the advanced notch filter functionality. Numerical calculations are also performed to explore the future feasibility of implementing a fully integrated microwave photonic filter that approaches the same level of link performance demonstrated in this work. This study is expected to provide a feasible design route to approach fully integrated microwave photonic filters with high link performance.