The performance of all active photonic devices today is greatly limited by loss. Here, we show that one can engineer a low loss path in a metal-clad lossy multi-mode waveguide while simultaneously achieving high-performance active photonic devices. We leverage non-Hermitian systems operating beyond the exceptional point to enable the redistribution of losses in a multi-mode photonic waveguide. Consequently, our multi-mode waveguide offers low propagation losses for fundamental mode while other higher order modes experience prohibitively high losses. Furthermore, we show an application of this non-Hermitian waveguide platform in designing power-efficient thermo-optic phase shifters with significantly faster response times than conventional silicon-based thermo-optic phase shifters. Our device achieves a propagation loss of less than 0.02 dB μm−1 for our non-Hermitian waveguide-based phase shifters with high performance efficiency of P π ⋅ τ = 19.1 mW μs. In addition, our phase shifters have significantly faster response time (rise/fall time), τ ≈ 1.4 μs, compared to traditional silicon based thermo-optic phase shifters.

中文翻译：

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为光通过非厄米介质扫清道路


当今所有有源光子器件的性能都受到损耗的极大限制。在这里，我们展示了人们可以在金属包层有损多模波导中设计一条低损耗路径，同时实现高性能有源光子器件。我们利用超出异常点运行的非厄米系统来实现多模光子波导中损耗的重新分布。因此，我们的多模波导为基模提供低传播损耗，而其他高阶模则经历极高的损耗。此外，我们展示了这种非厄米波导平台在设计节能热光移相器中的应用，其响应时间比传统的硅基热光移相器快得多。我们的器件实现了小于 0.02 dB μm 的传播损耗−1我们的基于非厄米波导的移相器具有高性能效率磷π ⋅ τ = 19.1 毫瓦微秒。此外，我们的移相器具有明显更快的响应时间（上升/下降时间）， τ与传统硅基热光移相器相比，约为 1.4 μs。