Integrated switches play a crucial role in the development of reconfigurable optical add-drop multiplexers (ROADMs) that have greater flexibility and compactness, ultimately leading to robust single-chip solutions. Despite decades of research on switches with various structures and platforms, achieving a balance between dense integration, low insertion loss (IL), and polarization-dependent loss (PDL) remains a significant challenge. In this paper, we propose and demonstrate a 32 × 4 optical switch using high-index doped silica glass (HDSG) for ROADM applications. This switch is designed to route any of the 32 inputs to the express ports or drop any channels from 32 inputs to the target 4 drop ports or add any of the 4 ports to any of the 32 express channels. The switch comprises 188 Mach-Zehnder Interferometer (MZI) type switch elements, 88 optical vias for the 44 optical bridges, and 618 waveguide-waveguide crossings with three-dimensional (3D) structures. At 1550 nm, the fiber-to-fiber loss for each express channel is below 2 dB, and across the C and L bands, below 3 dB. For each input channel to all 4 drop/add channels at 1550 nm, the loss is less than 3.5 dB and less than 5 dB across the C and L bands. The PDLs for all express and input channels to the 4 drop/add channels are below 0.3 dB over the C band, and the crosstalk is under −50 dB for both the C and L bands.

集成开关在可重构光分插复用器 (ROADM) 的开发中发挥着至关重要的作用，这种复用器具有更大的灵活性和紧凑性，最终形成强大的单芯片解决方案。尽管对各种结构和平台的开关进行了数十年的研究，但实现密集集成、低插入损耗 (IL) 和偏振相关损耗 (PDL) 之间的平衡仍然是一个重大挑战。在本文中，我们提出并演示了一种用于 ROADM 应用的使用高折射率掺杂石英玻璃 (HDSG) 的 32 × 4 光开关。该交换机设计用于将 32 个输入中的任何一个路由到 Express 端口，或者将 32 个输入中的任何通道分出到目标 4 个分出端口，或者将 4 个端口中的任何一个添加到 32 个 Express 通道中的任何一个。该开关包括 188 个马赫-曾德尔干涉仪 (MZI) 型开关元件、44 个光桥的 88 个光通孔以及 618 个具有三维 (3D) 结构的波导-波导交叉点。在 1550 nm 处，每个快速通道的光纤到光纤损耗低于 2 dB，并且在 C 和 L 频段上低于 3 dB。对于 1550 nm 处所有 4 个分出/分出通道的每个输入通道，损耗小于 3.5 dB，并且在 C 和 L 频段上损耗小于 5 dB。 C 频段上 4 个分出/分出通道的所有快速通道和输入通道的 PDL 均低于 0.3 dB，并且 C 和 L 频段的串扰均低于 -50 dB。