体相倏逝边缘耦合用于光纤到芯片的光学I/O

中文摘要 AI 辅助

共封装光学的光学输入/输出扩展受限于光纤到芯片的接口。传统边缘耦合具有低损耗和宽带宽的优点，但将通道限制在沿芯片端面的单行内。另一方面，表面耦合器要么窄带，要么难以高良率制造，并且重要的是，与后端金属布线竞争。在这项工作中，我们引入了体相边缘耦合，其中芯片边缘以三维方式结构化，使得光学耦合可以发生在二维区域而不是沿单线，为将多个波导与多芯光纤的多个纤芯接口提供了途径，同时保留了从芯片周边的光学接入。我们研究了一种基于全内反射（TIR）介导的倏逝耦合的单通道实现，通过KOH蚀刻硅腔的54.7°侧壁，耦合轮廓由楔形埋氧脊整形。时域有限差分模拟预测在1550 nm处峰值耦合效率为88%（-0.56 dB），1-dB带宽为86.45 nm，覆盖C波段。该设计还表现出约±2 μm的垂直对准容差，对高达5 μm的横向偏移具有弱敏感性，以及±0.8°的1-dB角度容差。反射的光场还提供了潜在的对准信号，为未来多芯实现中减少有源对准开销提供了途径。

英文摘要

Scaling optical input/output for co-packaged optics is limited by the fiber-to-chip interface. Conventional edge coupling offers low loss and broad bandwidth but confines channels to a single row along the chip facet. On the other hand, surface couplers are either narrowband or difficult to fabricate with high yield and, importantly, compete with back-end metal routing. In this work, we introduce volumetric edge coupling, in which the chip edge is structured in three dimensions so that optical coupling can occur over a two-dimensional region rather than along a single line, providing a route toward interfacing multiple waveguides with multiple cores of a multicore fiber while preserving optical access from the chip perimeter. We investigate a single-channel realization based on total-internal-reflection (TIR)-mediated evanescent coupling through the 54.7$^\circ$ sidewall of a KOH-etched silicon cavity, with the coupling profile shaped by a wedged buried-oxide ridge. Finite-difference time-domain simulations predict a peak coupling efficiency of 88% (-0.56 dB) at 1550 nm and a 1-dB bandwidth of 86.45 nm spanning the C-band. The design further exhibits a vertical alignment tolerance of approximately $\pm$2 $μ$m, weak sensitivity to transverse offsets up to 5 $μ$m, and a $\pm$0.8$^\circ$ 1-dB angular tolerance. The reflected optical field also provides a potential alignment signal, offering a path toward reduced active alignment overhead in future multicore implementations.

发表机构

• The American University in Cairo（开罗美国大学）
• James C. Wyant College of Optical Sciences, University of Arizona（亚利桑那大学詹姆斯·C·怀恩特光学科学学院）
• Department of Physics, University of Arizona（亚利桑那大学物理系）

机构由 AI 辅助整理，请以论文原文为准。