Aberration Theory of a Flat, Aplanatic Metalens Doublet and the Design of a Meta-Microscope Objective Lens

A theoretical approach for reducing multiple monochromatic aberrations using a flat metalens doublet is proposed and verified through ray tracing simulations. The theoretical relation between the Abbe sine condition and the generalized Snell's law is revealed in the doublet system. Starting from the Abbe aplanat design, minimization conditions of astigmatism and field curvature are derived. Based on the theory, a metalens doublet is semi-analytically optimized as a compact, practical-level meta-microscope objective lens working for a target wavelength. The proposed approach also reveals how to reduce lateral chromatism for an additional wavelength. The design degree of freedom and fundamental limits of the system are both rigorously analyzed in theory and verified through ray tracing simulations. It is expected that the proposed method will provide unprecedented practical opportunities for the design of advanced compact microscopic imaging or sensing systems.

Automated summary

This study proposes a theoretical method for reducing multiple monochromatic aberrations using a flat metalens doublet, which is validated through ray tracing simulations. The theoretical relationship between the Abbe sine condition and the generalized Snell's law is revealed in the doublet system. Minimization conditions for astigmatism and field curvature are derived from the Abbe aplanat design. By semi-analytically optimizing the metalens doublet, a compact and practical-level meta-microscope objective lens is realized for a target wavelength. The proposed method also addresses the reduction of lateral chromatism for an additional wavelength. The design freedom and fundamental limits of the system are rigorously analyzed and verified. It is anticipated that this method will offer unprecedented practical opportunities for the design of advanced compact microscopic imaging or sensing systems.