Metasurfaces and metamaterials are playing a growing role in the control of electromagnetic waves in the application of communication, display, and sensing technologies. However, designing photonic structures as the building blocks of these systems is typically a tedious trial-and-error process that requires extensive simulations with iterative sweeps in a multi-dimensional parameter space. To circumvent this conventional approach and substantially expedite the discovery and development of photonic structures, here we develop a framework leveraging both a deep generative model and a modified evolution strategy to automate the inverse design of engineered photonic materials and devices. The capacity of the proposed methodology is tested through the application to a case study, where metasurfaces in either continuous or discrete topologies are generated in response to customer-defined spectra at the input. Through a variational autoencoder, all potential patterns of unit structures are encoded into a continuous latent space. An evolution strategy is applied to vectors in the latent space to identify an optimized vector whose corresponding metasurface fulfills the design objective. The evaluation shows that over 95% accuracy can be achieved for all the unit patterns of the metasurfaces in the test dataset. Our scheme requires no prior knowledge of the geometry of the photonic structures, and, in principle, allows joint optimization of the dimensional parameters. As such, our work represents an efficient, on-demand, and automated approach for the inverse design of photonic structures with subwavelength features.

中文翻译：

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光子结构发现和设计的混合策略

在通信、显示和传感技术的应用中，超表面和超材料在控制电磁波方面发挥着越来越大的作用。然而，将光子结构设计为这些系统的构建块通常是一个繁琐的试错过程，需要在多维参数空间中进行大量的迭代扫描模拟。为了规避这种传统方法并大大加快光子结构的发现和发展，我们在这里开发了一个框架，利用深度生成模型和修改后的进化策略来自动化工程光子材料和设备的逆向设计。通过应用到案例研究来测试所提议方法的能力，其中连续或离散拓扑结构中的超表面是根据客户定义的输入光谱生成的。通过变分自编码器，单元结构的所有潜在模式都被编码到一个连续的潜在空间中。进化策略应用于潜在空间中的向量，以识别优化的向量，其相应的超表面满足设计目标。评估表明，测试数据集中超表面的所有单元模式都可以达到 95% 以上的准确率。我们的方案不需要光子结构几何的先验知识，并且原则上允许尺寸参数的联合优化。因此，我们的工作代表了一种高效、按需和自动化的方法，用于具有亚波长特征的光子结构的逆向设计。