In this letter, we designed and experimentally demonstrated a compact mode converter in silicon-on-insulator (SOI) waveguide based on conformal dielectric metasurface, which uses polygonal slot structure to manipulate the wavefront of guided modes. Mode conversion from TE0 to TE2 mode can be realized within an ultracompact size (~7.66 μm) by designing the arrow-like slot structure. With the help of asymmetric directional coupler (ADC), the TE0-to-TE2 mode converter was measured in the experiment with low insertion loss (IL) (<; 0.5 dB) and low crosstalk (CT) (<; -8.0 dB) from 1525 to 1565 nm. Moreover, a TE0-to-TE1 mode converter using another polygonal slot structure was also experimentally demonstrated. Our proposed mode converter shows great potential in high-density integration of photonic devices for on-chip mode control.

中文翻译：

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基于共形介电超表面的紧凑模式转换器的实验演示


在这封信中，我们设计并实验演示了一种基于共形介电超表面的绝缘体上硅（SOI）波导的紧凑型模式转换器，它使用多边形槽结构来操纵导​​模的波前。通过设计箭头状槽结构，可以在超紧凑尺寸（~7.66μm）内实现从TE0到TE2模式的模式转换。借助非对称定向耦合器（ADC），实验中测得TE0转TE2模式转换器具有低插入损耗（IL）（<；0.5 dB）和低串扰（CT）（<；-8.0） dB）从 1525 到 1565 nm。此外，还实验演示了使用另一种多边形槽结构的TE0到TE1模式转换器。我们提出的模式转换器在用于片上模式控制的光子器件的高密度集成方面显示出巨大的潜力。