Novel Time-Domain Inverse Design of High-Performance Nanophotonics with Broadband and Uniform Response

Traditional metasurface design relies heavily on expert intuition and experience, resulting in limited degrees of freedom and lengthy design processes. To address these challenges, adjoint optimization, one of the powerful inverse design methods, offers a promising alternative by optimizing design variables based on objective functions. However, most previous adjoint optimization works are based on the frequency-domain method, which requires numerous simulations per iteration for wideband applications, resulting in longer design times. This paper presents a novel time-domain inverse design method using adjustable pulses to overcome these limitations. The proposed method efficiently designs a high-performance metalens with uniform broadband.