Silicon Photonic Based Stacked Die Assembly Toward 4×200-Gbit/s Short-Reach Transmission

We presenta silicon photonic based stacked die assembly (SDA) compatible with the commercial complementary metal-oxide-semiconductor process. The SDA consists of a driver die and a transimpedance amplifier die, both populated onto a photonic integrated circuit die with a dimension of 5 mm×9 mm. The SDA is designed to be an O-band optical engine for a 4×200-Gbit/s parallel single-mode fiber short-reach transmission system. Performance of several pulse amplitude modulation (PAM) formats are evaluated and compared for the feasibility of 200-Gbit/s transmission. Aided by a Volterra nonlinear equalizer, the system experiment demonstrated that PAM-8 is a promising candidate for single lane 200-Gbit/s transmission with achieved bit error rate (BER) floor of 1.4×10−3. Instead of using costly optical amplifier, the system relies on the transimpedance amplifier on the SDA to boost up receiver sensitivity, which is shown to be −2.6 dBm and −2.0 dBm for 2-km and 10.5-km fiber transmissions respectively. The system impairments and noise sources are quantitatively discussed to facilitate further hardware improvement. We believe this is the first demonstration of net 200-Gbit/s transmission over 10 km without optical amplification, accomplished with silicon photonic integrated circuit and offline processing.