Title: Ultra-low-crosstalk Silicon Switches Driven Thermally and Electrically Show Chinese title

Title: 热驱动和电驱动的超低串扰硅开关

Abstract: Silicon photonic switches are widely considered as a cost-effective solution for addressing the ever-growing data traffic in datacenter networks, as they offer unique advantages such as low power consumption, low latency, small footprint and high bandwidth. Despite extensive research efforts, crosstalk in large-scale photonic circuits still poses a threat to the signal integrity. In this paper, we present two designs of silicon Mach-Zehnder Interferometer (MZI) switches achieving ultra-low-crosstalk, driven thermally and electrically. Each switch fabric is optimized at both the device and circuit level to suppress crosstalk and reduce system complexity. Notably, for the first time to the best of our knowledge, we harness the inherent self-heating effect in a carrier-injection-based MZI switch to create a pair of phase shifters that offer arbitrary phase differences. Such a pair of phase shifters induces matched insertion loss at each arm, thus minimizing crosstalk. Experimentally, an ultra-low crosstalk ratio below -40 dB is demonstrated for both thermo-optic (T-O) and electro-optic (E-O) switches. The T-O switch exhibits an on-chip loss of less than 5 dB with a switching time of 500 microseconds, whereas the E-O switch achieves an on-chip loss as low as 8.5 dB with a switching time of under 100 ns. In addition, data transmission of a 50 Gb/s on-off keying signal is demonstrated with high fidelity on the E-O switch, showing the great potential of the proposed switch designs. Show Chinese abstract

Abstract: 硅光开关因其低功耗、低延迟、小尺寸和高带宽的独特优势，被广泛认为是解决数据中心网络中不断增长的数据流量的经济高效方案。尽管进行了大量研究，大规模光子电路中的串扰仍然威胁着信号完整性。 本文提出了两种基于硅材料的马赫-曾德尔干涉仪（MZI）开关设计，这些开关通过热驱动和电驱动实现了超低串扰。每个开关结构在器件级和电路级都经过优化，以抑制串扰并降低系统复杂性。 值得注意的是，据我们所知，这是首次利用基于载流子注入的MZI开关的固有自加热效应，来创建一对提供任意相位差的移相器。这一对移相器在每个分支上诱导匹配的插入损耗，从而最小化串扰。 实验结果显示，热光（T-O）和电光（E-O）开关的串扰比均低于-40 dB。T-O开关的芯片损耗小于5 dB，切换时间为500微秒，而E-O开关的芯片损耗低至8.5 dB，切换时间小于100纳秒。 此外，在E-O开关上展示了50 Gb/s开关键控信号的高保真数据传输，显示出所提出开关设计的巨大潜力。