High Efficiency Visible Achromatic Metalens Design via Deep Learning

Metalenses with both achromatic performance and high focusing efficiency are always challenging, especially in visible range. In this work, a deep learning model is developed to accelerate the design of achromatic metalenses based on the geometric phase theory. During the building process of the phase response library and selection of the nano-structures, converted transmission coefficients including both phase and amplitude are considered in order to ensure the achromatic focusing, as well as a high focusing efficiency. To test the performance of the design developed from the deep learning model, numerical simulations are performed in the visible wavelengths from 428 to 652 nm, which show a focal length of 266 & mu;m with the deviation under 5%, and the average focusing efficiency reaches 52%.