Broadband Achromatic Metalens in Microwave Region by Inverse Design

In this work, an end-to-end hybrid inverse design framework combining data-driven inverse dispersion engineering with optimal random spatial multiplexing (ORSM) is proposed to achieve efficient design of high-performance ultra-broad band achromatic metalens without complex resonant designs. To test the performance of this method, a reflective metalens operating in microwave region is designed and simulated. Simulation results demonstrate achromatic focusing with a focal length of 215 mm and an average focusing efficiency of 52.91% over an ultra-broad operating band of 8-16 GHz. This method paves the way for the development of achromatic meta-devices for wideband microwave applications.