2.5D Silicon optical interposer for 400 Gbps electronic-photonic integrated circuit platform packaging

We demonstrate a 2.5D silicon optical interposer for the integration of multi-channel optical transceiver (TRx) operating at 50 Gbps/ch and more. It completes optical transceiver by flip-chip bonding the photonic ICs (PIC) such as Mach-Zehnder modulator (MZM) and Germanium-photodetector (Ge-PD), and electronic ICs (EIC) such as modulator driver and trans-impedance amplifier (TIA). In this study daisy chains of PICs and EICs are flip-chip bonded using wafer-level fabricated Cu-pillar μ-bumps. The optimally designed transmission line on the interposer shows insertion loss (S21) less than 1.5dB up to 50 GHz for the length of 8 mm. For the transmitter (Tx) packaged with PICs and EICs whose transmission line length is two times longer than that of packaged Rx shows less than 10dB of insertion loss up to 50 GHz. The packaged Tx successfully demonstrates eye diagram at 50 Gbps. Total data rate can increase to 400 Gbps and 800 Gbps and more by increasing the channel numbers.