Yang Shanglin, Fu Xin, Zhang Shiqi, Jia Hao, Niu Jiaqi, Zhang Lei, Yang Lin
Opt Express. 2025 Mar 10;33(5):10574-10590. doi: 10.1364/OE.555005.
The growing demand for data capacity in optical communication has heightened interest in mode-division multiplexing (MDM) technology, which provides high parallelism across spatial mode dimensions. Mode-insensitive variable optical attenuation is essential for advanced optical communication systems, ensuring consistent performance across multiple modes. However, current multimode variable attenuation devices are more complex in design and significantly larger than single-mode devices, limiting their integration potential. In this paper, we explore two mode-insensitive phase tuning schemes: waveguide widening and mode transformation. We validate these schemes by developing two compact, mode-insensitive variable optical attenuators (VOAs) on a silicon-on-insulator (SOI) platform. By fully leveraging uniquely inverse-designed mode manipulation devices, the VOAs achieve footprints comparable to their single-mode counterparts, overcoming the size barrier for multimode devices. Experimental results demonstrate robust mode-insensitive attenuation functionality with dynamic ranges of 38.4 dB and 19.6 dB for the two schemes, respectively. The proposed mode manipulation devices and VOAs exemplify the development of compact and efficient multimode components, supporting the ongoing trend toward enhanced integration of on-chip optical systems.
光通信中对数据容量不断增长的需求，提高了人们对模式分割复用（MDM）技术的兴趣，该技术可在空间模式维度上提供高并行性。模式不敏感可变光衰减对于先进光通信系统至关重要，可确保在多种模式下具有一致的性能。然而，当前的多模可变衰减器件设计更为复杂，且比单模器件大得多，限制了它们的集成潜力。在本文中，我们探索了两种模式不敏感相位调谐方案：波导加宽和模式变换。我们通过在绝缘体上硅（SOI）平台上开发两种紧凑的、模式不敏感可变光衰减器（VOA）来验证这些方案。通过充分利用独特的逆设计模式操纵器件，这些VOA实现了与单模同类器件相当的尺寸，克服了多模器件的尺寸障碍。实验结果表明，这两种方案分别具有38.4 dB和19.6 dB动态范围的强大模式不敏感衰减功能。所提出的模式操纵器件和VOA体现了紧凑高效多模组件的发展，支持了片上光学系统增强集成的持续趋势。
