Saito Yohei, Shikama Kota, Tsuchizawa Tai, Sato Norio
Opt Lett. 2022 Jun 15;47(12):2971-2974. doi: 10.1364/OL.456396.
An optical coupling method with high alignment tolerance by self-written waveguide (SWW) formation is a promising candidate for co-packaged optics (CPO) by silicon photonics (SiPh). However, conventional SWWs cannot be used with Si waveguides because visible light for SWW formation cannot radiate from the waveguide facet. Here, we devised a new, to the best of our knowledge, optical circuit with SiON waveguides for SWW formation from an SiPh chip. With our circuit, we achieved optical coupling between an SiPh chip and a standard single-mode fiber (SSMF) with a tapered SWW (TSWW). The lowest excess coupling loss compared to butt coupling with a high-numerical aperture (NA) fiber is approximately 0.6 dB over the C-band with the TSWW. In addition, our coupling method has higher alignment tolerances than butt coupling with a high-NA fiber (HNF).
通过自写波导（SWW）形成实现的具有高对准容差的光耦合方法，是硅光子学（SiPh）用于共封装光学（CPO）的一个有前景的候选方案。然而，传统的SWW不能与硅波导一起使用，因为用于形成SWW的可见光无法从波导端面辐射出来。在此，据我们所知，我们设计了一种新的光学电路，它带有用于从SiPh芯片形成SWW的SiON波导。利用我们的电路，我们通过锥形SWW（TSWW）实现了SiPh芯片与标准单模光纤（SSMF）之间的光耦合。与使用高数值孔径（NA）光纤进行对接耦合相比，在C波段使用TSWW时，最低额外耦合损耗约为0.6 dB。此外，我们的耦合方法比使用高NA光纤（HNF）进行对接耦合具有更高的对准容差。
