Gaussian decomposition physical modeling applied to metasurface-refractive hybrid systems

An approach for physical optics modeling of metasurface-refractive hybrid lenses is introduced. We propose the use of the Gaussian decomposition method to model vectorial wave propagation through refractive optics. Ray-path diffraction is automatically considered in this method, and complex input wavefront can be modeled as well. Several techniques are integrated to ensure great accuracy in decomposing an incoming vectorial wave into Gaussian beamlets, such as adaptive consideration of local wavefront principal curvatures and best-fit beam width estimation from local covariance matrix. Several designs examples are demonstrated to showcase the proposed method, including an inversely designed hybrid lens with complex polarization dependence.