Reducing power dissipation in electro-optic modulators is a key step for widespread application of silicon photonics to optical communication. In this work, we design Mach–Zehnder modulators in the silicon-on-insulator platform, which make use of slow light in a waveguide grating and of a reverse-biased p-n junction with interleaved contacts along the waveguide axis. After optimizing the junction parameters, we discuss the full simulation of the modulator in order to find a proper trade-off among various figures of merit, such as modulation efficiency, insertion loss, cutoff frequency, optical modulation amplitude, and dissipated energy per bit. Comparison with conventional structures (with lateral p-n junction and/or in rib waveguides without slow light) highlights the importance of combining slow light with the interleaved p-n junction, thanks to the increased overlap between the travelling optical wave and the depletion regions. As a surprising result, the modulator performance is improved over an optical bandwidth that is much wider than the slow-light bandwidth.

中文翻译：

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优化交错 pn 结以减少硅慢光调制器中的能量耗散

降低电光调制器的功耗是将硅光子学广泛应用于光通信的关键步骤。在这项工作中，我们在绝缘体上硅平台中设计了 Mach-Zehnder 调制器，它利用波导光栅中的慢光和沿波导轴具有交错触点的反向偏置 pn 结。在优化结参数后，我们讨论了调制器的完整仿真，以便在各种品质因数（例如调制效率、插入损耗、截止频率、光调制幅度和每比特耗散能量）之间找到适当的权衡。与传统结构（具有横向 pn 结和/或在没有慢光的肋形波导中）的比较突出了将慢光与交错 pn 结相结合的重要性，由于行进光波和耗尽区之间的重叠增加。令人惊讶的结果是，调制器性能在比慢光带宽宽得多的光带宽上得到了改善。