Silicon Photonic Coherent WDM Transmitter Employing Cascaded Micro-Ring Modulators on a Mach–Zehnder Interferometer

作者：Shuntaro Maeda, Takahiro Suganuma, Go Soma, Keita Hirashima, Takuya Okimoto, Yoshiaki Nakano, Takuo Tanemura · 发表于：Journal of Lightwave Technology · 年份：2025 · DOI：10.1109/jlt.2025.3629720 · 被引用次数：2 · 研究领域：Photonic and Optical Devices、Optical Network Technologies、Neural Networks and Reservoir Computing

The explosive growth of generative AI and cloud computing demands higher-speed transceivers at datacenter interconnects. Conventional wavelength-division-multiplexed (WDM) coherent systems enable large-capacity transmission but suffer from high complexity and cost due to multiple discrete components required at the transceivers. Optical frequency combs (OFCs) potentially offer a promising solution to provide cost-effective multi-wavelength sources, but compact WDM in phase quadrature (IQ) modulators compatible with OFC sources remain undeveloped. In this paper, we present a silicon photonic WDM IQ modulator using micro-ring modulators (MRMs) for OFC-based coherent systems. Through comprehensive numerical analysis, we reveal that the 4-MRMs/λ configuration allows nearly chirp-free coherent modulation both in the over- and under-coupled MRM driving conditions. A proof-of-concept experimental demonstration is achieved using a compact silicon photonic chip containing 16 integrated MRMs. Dual-wavelength 28-Gbaud quadrature phase-shift keying signals are generated through precise tuning of resonant wavelengths of all MRMs and phase biases.