Flip-chip integrated silicon photonic bridge chips for sub-picojoule per bit optical links

Silicon photonics holds tremendous promise as an energy and bandwidth efficient interconnect technology for chip-to-chip and within-chip communications in high-performance computing systems. In this paper, we present a low-parasitic microsolder-based flip-chip integration method used to integrate silicon photonic modulators and photodetectors with high-speed VLSI circuits using chips fabricated on vastly different technology platforms. Both the hybrid-integrated silicon photonic transmit (Tx) and receive (Rx) components were tested to demonstrate record sub-picojoule-per-bit performance at 5 Gbps.