[论文解读] A high-speed heterogeneous lithium tantalate silicon photonics platform

Margot Niels, Tom Vanackere+23 more|ArXiv.org|Mar 13, 2025

Photonic and Optical Devices被引用 4

一句话总结

本论文展示将铌酸锂集成到硅光子芯片上而不改变标准 CMOS 工艺，实现高速度调制、低驱动电压与低损耗。

ABSTRACT

The rapid expansion of cloud computing and artificial intelligence has driven the demand for faster optical components in data centres to unprecedented levels. A key advancement in this field is the integration of multiple photonic components onto a single chip, enhancing the performance of optical transceivers. Here, silicon photonics, benefiting from mature fabrication processes, has gained prominence. The platform combines modulators, switches, photodetectors and low-loss waveguides on a single chip. However, emerging standards like 1600ZR+ potentially exceed the capabilities of silicon-based modulators. To address these limitations, thin-film lithium niobate has been proposed as an alternative to silicon photonics, offering a low voltage-length product and exceptional high-speed modulation properties. More recently, the first demonstrations of thin-film lithium tantalate circuits have emerged, addressing some of the disadvantages of lithium niobate enabling a reduced bias drift and enhanced resistance to optical damage. As such, making it a promising candidate for next-generation photonic platforms. However, a persistent drawback of such platforms is the lithium contamination, which complicates integration with CMOS fabrication processes. Here, we present for the first time the integration of lithium tantalate onto a silicon photonics chip. This integration is achieved without modifying the standard silicon photonics process design kit. Our device achieves low half-wave voltage (3.5 V), low insertion loss (2.9 dB) and high-speed operation (> 70 GHz), paving the way for next-gen applications. By minimising lithium tantalate material use, our approach reduces costs while leveraging existing silicon photonics technology advancements, in particular supporting ultra-fast monolithic germanium photodetectors and established process design kits.

研究动机与目标

• 在数据中心面对日益增长的云/人工智能需求时，推动更快的光学组件。
• 实现调制器、开关、光探测器与低损耗波导在硅光子上的单片集成。
• 解决异质融合平台中的锂污染及 CMOS 兼容性问题。

提出的方法

• 在不修改标准 Si PIC 设计工具包的前提下，将铌酸锂集成到硅光子平台。
• 在器件中实现低半波电压 (Vπ) 为 3.5 V，插入损耗低至 2.9 dB。
• 证明高速度工作 (>70 GHz)，以实现超快光子信号。
• 利用现有的硅光子流程，支持超快单片锗探测器。

实验结果

研究问题

• RQ1 铌酸锂是否可以在不改变标准工艺设计工具包的情况下集成到硅光子上？
• RQ2 在硅上使用 LiTaO3 时，可实现的电光性能指标（Vπ、插入损耗）和带宽是多少？
• RQ3 该异质平台是否支持与当前硅光子生态系统兼容的超快光子功能？

主要发现

• 成功在不修改硅工艺设计工具包的前提下，将铌酸锂集成到硅光子芯片。
• 实现的低半波电压：3.5 V。
• 低插入损耗：2.9 dB。
• 高速度工作证明：>70 GHz。
• 该方法最小化 LiTaO3 材料用量，并利用现有的硅光子学进展（如锗探测器）。