Relative illumination engineering of near infrared metalens based on mixed-pitch meta-atom

We present and compare three metalens configurations, telecentric, non-telecentric, and telecentric with a mixed-pitch design, optimized for 940 nm operation with a 120° field of view. Comprehensive evaluation of modulation transfer function, distortion, and relative illumination (RI) reveals distinct trade-offs in performance. The telecentric design achieves the highest image quality but suffers from higher distortion and reduced RI. The non-telecentric design minimizes distortion and cost, though at the expense of resolution. By using the relative illumination uniform engineering, the mixed-pitch design offers a balanced solution, enhancing edge resolution and RI (up to 87% @ FoV = 45°), making it well-suited for wide-angle, high-performance imaging. This study provides design guidelines for tailoring metalenses to application-specific needs.