Hybrid integration of material-optimized photonics for fully integrated microwave photonic links

Integrated microwave photonics (MWP) is actively investigated due to its advantages such as compact footprint, wide bandwidth, and reconfigurability. However, fully integrated MWP systems demand a diverse set of advanced performance metrics—high optical power, broad modulation bandwidth, and low noise—that fundamentally exceed the physical limits of any single material platform. To overcome these bottlenecks, we present the development of a fully integrated MWP link through an advanced hybrid integration strategy. In this work, we have heterogeneously integrated the InP-based lasers, lithium niobate (LN) electro-optic modulators, Ge photodetectors, and a silica optical adapter onto a silicon photonic platform. The proposed approach leverages heterogeneous and hybrid integration to realize a fully integrated chip unifying InP, Si, Ge, silicon nitride, LN, and silica material platforms. Reliable optical interconnectivity is experimentally demonstrated, with low coupling losses of 1.46 dB and 1.10 dB achieved for the InP-to-Si and Si-to-SiO ₂ hybrid interfaces, respectively. Furthermore, the integrated active components exhibit stable high-frequency characteristics, with the modulator and photodetector delivering 3-dB bandwidths of 48.48 GHz and 45.27 GHz, respectively. Ultimately, a system-level spurious-free dynamic range of 91.9 dB· Hz²/3 is achieved. This study provides a scalable fabrication route for integrated MWP, targeting applications in broadband communication, sensing, and signal processing systems.