We examine the use of foundry process optical waveguide couplers in making 1 × 2 optical switches. The concept involves a post-foundry process to provide a moveable dielectric load over one of the waveguides in the coupler, such that the dielectric load changes the propagation constant of the affected waveguide depending on its proximity to the waveguide. Coupled mode theory is employed to explain the operation of the switch and identify key requirements of the dielectric load. Finite difference time domain simulations are employed to verify that the concept is viable for two standard photonic integrated circuit platforms. The concept ensures that the optical signals are always constrained within the high-quality foundry process waveguides while also allowing the material and lithography requirements for the layer in which the movable load is realized to be relaxed. Results show that a contrast between the switch ports of >20 dB is possible with relaxed tolerances for the dielectric load layer, at an operating wavelength of 1550 nm. We envision that the dielectric load would be moved by a micro-electromechanical systems actuator. Having the optical signals always within the foundry waveguides will permit fabrication of high-performance mechanically switched optical systems by a wide range of facilities.

中文翻译：

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基于铸造工艺光波导的电介质负载 1 × 2 定向耦合器开关的灵敏度分析

我们研究了铸造工艺光波导耦合器在制造 1 × 2 光开关中的使用。该概念涉及铸造后工艺，以在耦合器中的波导之一上提供可移动的介电负载，使得介电负载根据其与波导的接近程度改变受影响的波导的传播常数。采用耦合模式理论来解释开关的操作并确定介电负载的关键要求。采用有限差分时域仿真来验证该概念对于两个标准光子集成电路平台是否可行。该概念确保光信号始终被限制在高质量铸造工艺波导内，同时还允许放宽对实现可移动负载的层的材料和光刻要求。结果表明，在 1550 nm 的工作波长下，在放宽介电负载层容差的情况下，交换机端口之间的对比度可以达到 >20 dB。我们设想介电负载将由微机电系统致动器移动。让光信号始终位于铸造波导内将允许通过各种设施制造高性能机械切换光学系统。工作波长为 1550 nm。我们设想介电负载将由微机电系统致动器移动。让光信号始终位于铸造波导内将允许通过各种设施制造高性能机械切换光学系统。工作波长为 1550 nm。我们设想介电负载将由微机电系统致动器移动。让光信号始终位于铸造波导内将允许通过各种设施制造高性能机械切换光学系统。