We experimentally demonstrate a digital-to-analog-converter-less (DAC-less) vestigial sideband (VSB) 4-level pulse amplitude modulation (PAM4) transmission system for data center interconnects (DCIs) using a silicon photonic (SiP) multi-electrode Mach-Zehnder modulator (ME-MZM) based DAC-less transmitter and a VSB self-coherent receiver. The impacts of linear and nonlinear impairments on the proposed system and their mitigation methods are comprehensively studied. By using Kramer-Kronig (KK) detection, frequency domain chromatic dispersion compensation, and short-memory time domain Volterra equalization at the receiver, we report a 112 Gb/s PAM4 transmission over 40 km standard single mode fiber (SSMF) with a bit error rate (BER) below the 7% overhead (OH) hard-decision forward error correction threshold of 3.8 × 10⁻³, and a 120 Gb/s PAM4 transmission over 80 km SSMF with a BER below the 20% OH soft-decision forward error correction threshold of 2 × 10⁻², without any transmitter side digital signal processing such as pre-emphasis and pulse shaping.

中文翻译：

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用于基于数据中心互连的100 Gb / s PAM4传输系统，使用基于SiP ME-MZM的无DAC发射器和VSB自相干接收器

我们通过实验证明了采用硅光子（SiP）多模数转换器的数据中心互连（DCI）的无数模转换器（DAC）残留边带（VSB）4级脉冲幅度调制（PAM4）传输系统基于Mach-Zehnder调制器（ME-MZM）的无DAC发射器和VSB自相干接收器。全面研究了线性和非线性损伤对所提出系统的影响及其缓解方法。通过使用接收器的Kramer-Kronig（KK）检测，频域色散补偿和短时域Volterra均衡，我们报告了40 km标准单模光纤（SSMF）上的112 Gb / s PAM4传输速率，错误率（BER）低于7％开销（OH）硬决策前向纠错阈值3.8×10 ^-3，并在80 km SSMF上以120 Gb / s的PAM4传输，且BER低于2×10 ^-2的20％OH软判决前向纠错阈值，而无需任何诸如预加重和脉冲整形的发射机侧数字信号处理。