Misaligned period method for dual-layer broadband achromatic metalens

A dual-layer metalens has the advantage that the parameters of each layer can be adjusted with no influence on the other layers. Based on the dual-layer structure, an achromatic metalens has been designed. One layer of the metalens can realize the phase distribution at a fixed wavelength, and the other layer offers the compensation for different wavelengths. In this article, we propose that the misalignment between the layers can improve the performance of achromatic metalens. This method can be used to design high-performance metalenses.