Controllable Structurally Randomized Cu Mesh Films for EMI-Shielded Optical Windows with Slight Imaging Quality Degradation

• • Structural randomization reduces normalized higher-order diffraction energy to −3.93 dB, effectively suppressing ghost images in optical windows. • • The most randomized Cu mesh film achieves an ultra-low sheet resistance of 3.31 Ω/sq and high visible light transmittance of 88.7% at 550 nm, yielding an exceptional figure of merit (FoM=913.69). • • EMI shielding effectiveness averages 33.18 dB across the X-band (8–12 GHz), meeting robust shielding requirements for sensitive electronics. • • Imaging resolution degrades minimally from 80.6 to 71.8 lp/mm, demonstrating that randomization preserves optical quality while enhancing EMI shielding.