Coherent optical communication is considered as an indispensable solution to the ever-increasing demand for higher data rates. To reduce the cost and form factor of coherent transceivers, full integration of photonic devices including lasers, modulators, amplifiers, photodetectors, and other components is necessary. However, as fabricating optical isolators on chip remains extremely challenging, optical feedback, which can degrade the coherence of semiconductor lasers, becomes the main obstacle, thwarting large-scale photonic integration. An appealing solution to such a problem is to use semiconductor lasers with intrinsic insensitivity to optical feedback as the integrated light sources. The heterogenous Si/III-V lasers, with their built-in high-Q resonators, are expected to possess a robustness to optical feedback which exceeds by several orders of magnitude compared to commercial III-V distributed feedback (DFB) lasers, which will be validated here. We present data showing that the heterogeneous Si/III-V lasers can preserve their phase coherence under much larger optical feedback and therefore function without severe degradation in isolator-free coherent optical communication systems.

中文翻译：

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使用无隔离器异质 Si/III-V 激光器的高速相干光通信


相干光通信被认为是满足不断增长的更高数据速率需求的不可或缺的解决方案。为了降低相干收发器的成本和外形尺寸，必须完全集成光子器件，包括激光器、调制器、放大器、光电探测器和其他组件。然而，由于在芯片上制造光学隔离器仍然极具挑战性，光学反馈会降低半导体激光器的相干性，成为阻碍大规模光子集成的主要障碍。解决这一问题的一个有吸引力的解决方案是使用对光反馈本质上不敏感的半导体激光器作为集成光源。异质 Si/III-V 激光器具有内置的高 Q 谐振器，预计将具有比商用 III-V 分布式反馈 (DFB) 激光器高出几个数量级的光学反馈鲁棒性，这将在这里进行验证。我们提供的数据表明，异质 Si/III-V 激光器可以在更大的光学反馈下保持其相位相干性，因此在无隔离器的相干光通信系统中运行时不会出现严重退化。