High efficiency metalens design using wavefront error optimization

Conventional metalens design is based on the library where phases and transmissions of the meta-atoms are calculated with the periodic boundary condition. And the most suitable meta-atom is picked up from the library ignoring its environment. However, the coupling between adjacent meta-atoms produces the phase error, leading to low efficiency and scattering of the metalens. We proposed a method of numerical optimization of the wavefront error by adjusting the meta-atoms size, which reduces phase errors leading to higher efficiency compared to the conventional metalens design. This method is scalable for a large size metalens and for metalens with an arbitrary phase profile.