Pattern search algorithm-aided structural color Sb2S3-based dynamic hybrid all-dielectric metasurface

The versatility and dynamic tunability of reconfigurable photonic devices hold paramount significance in optics. Nevertheless, most such dynamically adjustable all-dielectric metasurfaces, particularly those utilized in structural color applications, are usually resonators made exclusively of phase-change materials. The elevated absorption coefficients exhibited by phase-change materials in the short-wavelength band (particularly within the blue light range) often culminate in suboptimal performance for generating colors. To address this challenge, we designed a hybrid all-dielectric metasurface that achieved reflectivities of 60%, 75%, and 96% across blue, green, and red-light bands, respectively and achieved dynamic tunability of the metasurface by generating chromatic aberrations of 19.626, 3.341, and 17.354 via the reversible phase transition of Sb2S3. The device exhibits good angular robustness, maintaining nearly constant color within a viewing angle range of ±20°. Meanwhile, we employ a pattern search algorithm to accelerate the inverse design process of metasurfaces. The algorithm can reduce the design time by a factor of at least two orders of magnitude relative to the genetic algorithm, substantially improving design efficiency. The algorithm applies to high degree-of-freedom inverse design problems for intricate physical systems with similar design relationships. It offers a promising avenue for rapid and dependable optical device design.