Photonic-dispersion neural networks for inverse scattering problems

• 作者: Tongyu Li Ang Chen Lingjie Fan Minjia Zheng Jiajun Wang Guopeng Lu Maoxiong Zhao Xinbin Cheng Wei Li Xiaohan Liu Haiwei Yin Lei Shi Jian Zi
• 来源期刊: 光：科学与应用（英文版）
• 年，卷（期）: 2021,（10）
• 所属期刊栏目: Articles
• 页码范围: 1819-1828
• 页数: 10页
• 语种: 英文

摘要

Inferring the properties of a scattering objective by analyzing the optical far-field responses within the framework of inverse problems is of great practical significance. However, it still faces major challenges when the parameter range is growing and involves inevitable experimental noises. Here, we propose a solving strategy containing robust neuralnetworks- based algorithms and informative photonic dispersions to overcome such challenges for a sort of inverse scattering problem—reconstructing grating profiles. Using two typical neural networks, forward-mapping type and inverse-mapping type, we reconstruct grating profiles whose geometric features span hundreds of nanometers with nanometric sensitivity and several seconds of time consumption. A forward-mapping neural network with a parameters-to-point architecture especially stands out in generating analytical photonic dispersions accurately, featured by sharp Fano-shaped spectra. Meanwhile, to implement the strategy experimentally, a Fourier-optics-based angle-resolved imaging spectroscopy with an all-fixed light path is developed to measure the dispersions by a single shot, acquiring adequate information. Our forward-mapping algorithm can enable real-time comparisons between robust predictions and experimental data with actual noises, showing an excellent linear correlation (R2 > 0.982) with the measurements of atomic force microscopy. Our work provides a new strategy for reconstructing grating profiles in inverse scattering problems.