We demonstrate tunable broadband two-mode power dividers based on a wavelength-insensitive coupler for a mode-division multiplexing system. Ultra-small ${{\rm{TE}}_0} {-} {{\rm{TE}}_1}$ and ${{\rm{TE}}_0} {-} {{\rm{TE}}_2}$ mode dividers based on Si-wire waveguides are designed based on the coupled-mode theory. Tunability is achieved by using the thermo-optic effect. In both dividers, arbitrary branching ratios can be realized over a wide wavelength range. We experimentally demonstrated for the first time, to the best of our knowledge, a tunable ${{\rm{TE}}_0} {-} {{\rm{TE}}_1}$ mode divider based on Si-wire waveguides. From the experimental results, an arbitrary branching ratio can be achieved by adjusting the injection current to a TiN heater placed on top of one of the delay lines.

中文翻译：

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基于波长不敏感耦合器的可调谐宽带模式功率分配器，利用热光效应在模分复用网络中进行灵活的模态功率调整

我们为模分复用系统演示了一种基于波长不敏感耦合器的可调宽带二模功率分配器。超小型$ {{\ rm {TE}} _ 0} {-} {{\ rm {TE}} _ 1} $和$ {{\ rm {TE}} _ 0} {-} {{\ rm {TE} } _2} $基于Si-wire波导的模式分频器是基于耦合模式理论设计的。通过使用热光效应可以实现可调谐性。在两个分光器中，可以在较宽的波长范围内实现任意的分支比。据我们所知，我们首次通过实验证明了可调整的$ {{\ rm {TE}} _ 0} {-} {{\ rm {TE}} _ 1} $基于硅线波导的模式分频器。根据实验结果，可以通过调节流向位于延迟线之一顶部的TiN加热器的注入电流来获得任意的分支比。