Xu Siyu, Liu Weixin, Le Xianhao, Lee Chengkuo
Department of Electrical & Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117583, Singapore.
Center for Intelligent Sensors and MEMS, National University of Singapore, 4 Engineering Drive 3, Singapore 117608, Singapore.
Nano Lett. 2024 Sep 20. doi: 10.1021/acs.nanolett.4c03622.
Piezo-optomechanics presents a promising route to convert microwave signals to the optical domain, implementing processing tasks that are challenging using conventional electronics. The surge of integrated photonics facilitates the exploitation of localized light-sound interactions toward new technological paradigms. However, efficient acousto-optic interaction has yet to be fully exploited in silicon due to the absence of piezoelectricity, despite its maturity in photonic integrated circuits. Here, we introduce a distinctive acousto-optic scheme to supplement silicon photonic devices through heterogeneous integration with lithium niobate (LN). Utilizing LN as an efficient acoustic pump to harness the inherently exceptional photoelasticity in silicon, we demonstrate efficient microwave-to-acoustic transduction, ultimately achieving a modulation figure-of-merit of ∼ 0.496 V·cm. This efficient modulation scheme is further extended to implement non-reciprocal intermodal modulation. The proposed hybrid integration route opens new possibilities for tailoring photon-phonon interactions in silicon, consolidating acousto-optic technology in multifunctional integrated photonics.
压光力学为将微波信号转换到光域提供了一条很有前景的途径，可实现一些使用传统电子学难以完成的处理任务。集成光子学的蓬勃发展促进了利用局域声光相互作用来实现新的技术范式。然而，尽管硅基光子集成电路已经成熟，但由于缺乏压电性，高效的声光相互作用在硅中尚未得到充分利用。在这里，我们引入一种独特的声光方案，通过与铌酸锂（LN）进行异质集成来补充硅光子器件。利用LN作为高效的声泵来利用硅中固有的优异光弹性，我们展示了高效的微波到声的转换，最终实现了约0.496 V·cm的调制品质因数。这种高效的调制方案进一步扩展以实现非互易的模式间调制。所提出的混合集成途径为在硅中定制光子 - 声子相互作用开辟了新的可能性，巩固了多功能集成光子学中的声光技术。
