Efficient nanophotonic devices optimization using deep neural network trained with physics-based transfer learning methodology.

We propose a neural network (NN)-based surrogate modeling framework for photonic device optimization, especially in domains with imbalanced feature importance and high data generation costs. Our framework, which comprises physics-based transfer learning (PBTL)-enhanced surrogate modeling and scalarized multi-objective genetic algorithms (GAs), offers a generalizable solution for photonic design automation with minimal data resources. To validate the framework, we optimize quantum cascade laser (QCL) structures consisting of two regions: active and injection, which have different levels of feature importance. The optimization targets include five key QCL performance metrics, resulting in multiple local optimum structures. To address the challenge of multiple local optima in the output latent space, we integrate a deep neural network total predictor (DNN-TP) with a GA. By replacing computationally expensive numerical simulations with the DNN-TP model, the optimization achieves a speed-up of over 80,000 times, allowing large-scale exploration of the design space. To improve model generalization with limited data, we introduce PBTL, which transfers knowledge from a DNN core predictor (DNN-CP) trained on active-region structures. This approach yields a 0.69% increase in prediction accuracy, equivalent to a 50% reduction in training data requirements, and leads to generate more feasible device structure with 60% improvement in evaluation metric during optimization.