“…The phrase “deep learning” (DL) was first coined by Hinton [ 26 ], by which remarkable achievements have been obtained in the fields of computer vision [ 27 ], speech recognition [ 28 ], decision making [ 29 ] and so on, showing a promising future for dealing with the problems of the inverse design of realistic structures and materials, as the underlying nature steps away from the data-driven path. Stimulated by this interactive feature without concurrent numerical simulations, the DL model based on a neural network has been widely applied to study the electromagnetic response for given structures [ 30 , 31 ], the constitutive of solid materials [ 32 ], the manipulation of low-frequency acoustic waves [ 33 ], the photonic and phononic topological state [ 34 , 35 ], the electric and magnetic dipoles [ 36 ] and so on, which further promotes the development of the optimization of PCs and MMs for anticipated band gap properties. Regarding one-dimensional PnCs and elastic MMs, various DL NNs based on the multilayer perceptron (MLP) have been established.…”