Novel Monolithic All-Silicon Coherent Transceiver Sub-Assembly Based on Ring Modulators

We demonstrate a novel monolithic coherent transceiver sub-assembly based on ring modulators, realized with Si photonic BiCMOS technology which allows monolithic integration of Si photonic integrated circuits and high-performance BiCMOS electronics. The transmitter consists of a ring modulator assisted Mach-Zehnder interferometer (RaMZI) and modulator driver electronics. The complex electro-optic modulation characteristics of the Si ring modulators (RMs) used for the transmitter are carefully investigated. The receiver includes the photonic components such as the Ge photodiodes and multimode interferometer (MMI) as well as the receiver front-end electronics such as transimpedance amplifier (TIA), variable gain amplifier (VGA) and output buffers. The performance evaluation of the novel monolithic all-silicon coherent transceiver sub-assembly based on ring modulators is carried out with a 28-Gbaud quadrature-phase-shift keying (QPSK) modulation signal.