毫米尺度复杂调制集成布拉格光栅的高效仿真：基于分层局部周期本征模展开

中文摘要 AI 辅助

我们提出了一种结构感知的分层局部周期本征模展开（HLP-EME）框架，用于高效仿真绝缘体上硅平台上具有复杂调制的毫米尺度集成布拉格光栅（IBGs）。HLP-EME将连续变化的光栅参数分布离散化为分段常数块，并利用由此产生的物理光栅结构的局部周期性，在每个块内重用代表周期的S矩阵。该策略将毫米尺度IBGs的全器件仿真时间缩短至几分钟，相比传统三维时域有限差分（3D-FDTD）仿真，加速比超过三个数量级。该方法适用于多种IBG配置，包括模内光栅、模式转换多模光栅以及光栅辅助反向耦合器。实验结果验证了多个复杂调制IBGs的预测反射谱以及一个代表性设计的反射相位响应。该框架进一步扩展到弯曲波导，并成功捕捉了毫米长、高斯变迹螺旋IBGs中由曲率引起的光谱畸变。结合全矢量建模与高计算效率，HLP-EME为设计和优化长而复杂的基于IBG的光子器件提供了强大工具。

英文摘要

We propose a structure-aware, hierarchical locally periodic eigenmode expansion (HLP-EME) framework for efficiently simulating millimeter-scale integrated Bragg gratings (IBGs) with complex modulation on silicon-on-insulator platforms. HLP-EME discretizes continuously varying grating parameter profiles into piecewise-constant blocks and exploits the resulting local periodicity of the physical grating structure by reusing the S-matrix of a representative period within each block. This strategy reduces full-device simulation times for millimeter-scale IBGs to a few minutes, providing a speedup exceeding three orders of magnitude over conventional 3D-FDTD simulations. The method accommodates diverse IBG configurations, including intra-mode gratings, mode-converting multimode gratings and grating-assisted contra-directional couplers. Experimental results validate the predicted reflection spectra of several complex-modulated IBGs and the reflection phase response of one representative design. The framework is further extended to curved waveguides and successfully captures curvature-induced spectral distortions in millimeter-long, Gaussian-apodized spiral IBGs. Combining full-vectorial modeling with high computational efficiency, HLP-EME provides a powerful tool for designing and optimizing long, complex IBG-based photonic devices.

发表机构

• Hefei University of Technology（合肥工业大学）
• Ningbo University of Technology（宁波工程学院）

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