This theoretical simulation paper presents designs and projected performance of ∼1550-nm silicon-on-insulator (SOI) and ∼2000-nm Ge-on-Si-on-nitride and Ge-on-nitride 2×2 optical crossbar switches based upon a three-waveguide coupler in which the central waveguide is a nanobeam actuated by the thermo-optical (TO) effect. A TO heater stripe is located atop the central nanobeam. To implement accurate and realistic designs, the 3D finite difference time domain approach was employed. The metrics of crossbar switching, insertion loss (IL) and crosstalk (CT) were evaluated for choices of 3-waveguide structure parameters and TO-induced index changes. The predicted ILs and CTs were excellent, enabling the designed devices to be considered as fundamental building blocks in wavelength-division-multiplexed cross-connect (WXC) applications. Proposed here are compact, nonblocking space-and-wavelength routing switches to be constructed in a monolithic, industry-standard SOI chip (and in Ge-on-SON and GON chips). Specifics are given for realizing 16 × 16 × Mλ WXCs as well as reconfigurable, multi-resonant, programmable hexagonal and diamond meshes.

中文翻译：

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紧凑型谐振2×2纵横制开关，使用三个耦合的波导和一个中央纳米束

该理论仿真论文介绍了基于以下条件的〜1550 nm绝缘体上硅（SOI）以及〜2000 nm Ge-on-Si-on-Si氮化物和Ge-on-氮化物2×2光学交叉开关的设计和预期性能。一种三波导耦合器，其中中央波导是由热光（TO）效应驱动的纳米束。TO加热器条位于中央纳米束的顶部。为了实现准确而逼真的设计，采用了3D时域有限差分法。评估了交叉开关，插入损耗（IL）和串扰（CT）的指标，以选择3波导结构参数和TO引起的折射率变化。预测的IL和CT优异的性能，使设计的器件被视为波分复用交叉连接（WXC）应用中的基本构件。这里提出的紧凑，无阻塞的空间和波长路由交换机将以单片，行业标准的SOI芯片（以及Ge-on-SON和GON芯片）构建。细节给出用于实现16×16×M λ WXCs以及可重新配置的，多谐振，可编程六边形和菱形的网格。