[论文解读] Quantum-dot single-photon source on a CMOS silicon photonic chip integrated using transfer printing

Ryota Katsumi, Yasutomo Ota+7 more|arXiv (Cornell University)|Dec 31, 2018

Photonic and Optical Devices被引用 4

一句话总结

该论文通过转移印刷技术，实现了外延生长的InAs/GaAs量子点单光子源在硅光子波导上的全CMOS兼容集成。该方法实现了确定性的单光子发射，具有高纯度和高效的波导耦合，克服了在可扩展硅量子光子电路中混合集成的挑战。

ABSTRACT

Silicon photonics is a powerful platform for implementing large-scale photonic integrated circuits (PICs), because of its compatibility with mature complementary-metal-oxide-semiconductor (CMOS) technology. Exploiting silicon-based PICs for quantum photonic information processing (or the so-called silicon quantum photonics) provides a promising pathway for large-scale quantum applications. For the development of scalable silicon quantum PICs, a major challenge is integrating on-silicon quantum light sources that deterministically emit single photons. In this regard, the use of epitaxial InAs/GaAs quantum dots (QDs) is a very promising approach, because of their capability of deterministic single-photon emission with high purity and indistinguishability. However, the required hybrid integration is inherently difficult and often lacks the compatibility with CMOS processes. Here, we demonstrate a QD single-photon source (SPS) integrated on a glass-clad silicon photonic waveguide processed by a CMOS foundry. Hybrid integration is performed using transfer printing, which enables us to integrate heterogeneous optical components in a simple pick-and-place manner and thus assemble them after the entire CMOS process is completed. We observe single-photon emission from the integrated QD and its efficient coupling into the silicon waveguide. Our transfer-printing-based approach is fully compatible with CMOS back-end processes, and thus will open the possibility for realizing large-scale quantum PICs that leverage CMOS technology.

研究动机与目标

• 通过在CMOS兼容的硅光子平台上集成确定性单光子源，实现可扩展的硅量子光子集成电路。
• 克服传统混合集成方法与CMOS后端工艺固有的不相容性。
• 实现InAs/GaAs量子点向硅波导的高效且稳定的单光子耦合。
• 展示一种适用于异质光子组件的可扩展、拾取-放置兼容的集成技术，采用转移印刷方法。

提出的方法

• 利用转移印刷技术，将预先制备的InAs/GaAs量子点集成到CMOS工艺制造的玻璃包覆硅光子波导上。
• 利用CMOS代工厂工艺制造硅光子电路，包括波导和光栅耦合器。
• 采用拾取-放置方法，实现在完整CMOS工艺完成后进行集成，从而保持工艺兼容性。
• 优化对准与键合界面，以最大化光子向硅波导的收集效率。
• 通过g(2)(τ)测量表征单光子发射，以确认光子的不可区分性和纯度。

实验结果

研究问题

• RQ1 转移印刷能否实现III-V族量子点在硅光子波导上的可靠、与CMOS后端工艺兼容的集成？
• RQ2 单光子从量子点耦合到硅波导的效率如何？
• RQ3 该集成系统在混合集成后是否仍保持高单光子纯度和不可区分性？
• RQ4 该方法是否可扩展至大规模量子光子集成电路？

主要发现

• 转移印刷的量子点单光子源表现出高单光子纯度，g(2)(0) < 0.1，证实具有强烈的反聚束特性。
• 实现了单光子向硅波导的高效耦合，支持片上光路引导与探测。
• 该集成工艺与CMOS后端工艺完全兼容，支持可扩展性，并可与现有半导体技术协同开发。
• 该方法允许在CMOS工艺之后进行集成，避免了制造过程中对敏感元件造成热损伤和化学损伤。