To achieve any specified band gap structure around target frequency, a new photonic crystals (PhC) topological design strategy is proposed. In the design optimization model, a band gap index that measures the minimal signed distances between the specified frequency and any two adjacent orders of frequencies is proposed, and the topology of PhC unit cell is represented with a low number of design variables through the material-field series-expansion. Then the sequential Kriging-based algorithm is adopted for solving the multi-peak and nondifferentiable optimization problems. Based on the numerical implementation of the proposed optimization method, the PhC unit cells are designed to provide band gaps precisely matching any specified central frequency value. The optimized unit cell designs are easily assembled to achieve a PhC device with the large relative band gap.

中文翻译：

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指定目标频率下的光子带隙材料拓扑设计

为了在目标频率附近实现任何指定的带隙结构，提出了一种新的光子晶体 (PhC) 拓扑设计策略。在设计优化模型中，提出了测量指定频率与任意两个相邻频率阶数之间的最小符号距离的带隙指数，并通过材料-领域系列扩展。然后采用基于序贯克里金法的算法求解多峰不可微优化问题。基于所提出的优化方法的数值实现，PhC 单元被设计为提供精确匹配任何指定中心频率值的带隙。