Hybrid integrated photonics using bulk acoustic resonators
Hybrid integrated photonics using bulk acoustic resonators
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DOI：
10.1038/s41467-020-16812-6
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发表时间：
2020-06-17
影响因子：
16.6
通讯作者：
Bhave, Sunil A.
中科院分区：
文献类型：
--
作者：
Tian, Hao;Liu, Junqiu;Bhave, Sunil A.
基于Si 3 N4波导的集成光子器件允许利用非线性频率转换，表现出低传播损耗，并导致了紧凑型原子钟，超快测距和光谱学的进步。然而，普克尔斯效应的缺乏对实现Si 3 N4的高速调制提出了主要挑战。在这里，微波频率声光调制是通过激发光子堆中的高泛音体声波谐振（HBAR）来实现的。虽然HBAR在现代通信和超导电路中无处不在，但这是它首次被集成在光子集成芯片上。紧密的垂直声学限制释放了横向设计的自由度，并实现了可忽略的串扰和保持低光损耗。这种混合HBAR纳米光子平台可以立即应用于具有合成维度的拓扑光子学，紧凑型光电振荡器和微波-光学转换器。作为应用，我们利用时空调制技术制作了一个氮化硅基光隔离器，隔离度超过17 dB。在这里，作者演示了使用高泛音体声波谐振的氮化硅微谐振器的声光调制，允许通过声波在GHz范围内进行调制。作为一个应用，一个光隔离器被证明与17 dB的非互易性。
Integrated photonic devices based on Si3N4 waveguides allow for the exploitation of nonlinear frequency conversion, exhibit low propagation loss, and have led to advances in compact atomic clocks, ultrafast ranging, and spectroscopy. Yet, the lack of Pockels effect presents a major challenge to achieve high-speed modulation of Si3N4. Here, microwave-frequency acousto-optic modulation is realized by exciting high-overtone bulk acoustic wave resonances (HBAR) in the photonic stack. Although HBAR is ubiquitously used in modern communication and superconducting circuits, this is the first time it has been incorporated on a photonic integrated chip. The tight vertical acoustic confinement releases the lateral design of freedom, and enables negligible cross-talk and preserving low optical loss. This hybrid HBAR nanophotonic platform can find immediate applications in topological photonics with synthetic dimensions, compact opto-electronic oscillators, and microwave-to-optical converters. As an application, a Si3N4-based optical isolator is demonstrated by spatiotemporal modulation, with over 17 dB isolation achieved. Here, the authors demonstrate acousto-optic modulation of silicon nitride microring resonators using high-overtone bulk acoustic wave resonances, allowing modulation in the GHz range via acoustic waves. As an application, an optical isolator is demonstrated with 17 dB non-reciprocity.