Laser-optical-field-modulation fabricating large-aperture dual-band antireflection windows for MWIR and LWIR imaging

Abstract Dual-band antireflection (DBAR) windows based on surface microstructures offer a promising solution for mid-wave infrared (MWIR) and long-wave infrared (LWIR) co-aperture composite imaging. However, micro-nano manufacturing technology faces significant challenges in efficiently producing highly uniform microstructures with characteristic dimensions of ∼1 μm across hundreds of millimeters. Here, we report a laser optical field modulation (LOFM) technology for the rapid manufacture of ultra-large-scale arrays of antireflection microholes (ARMHs) on large-aperture and non-perfectly planar windows. LOFM technology, which modulates laser pulses in both temporal and spatial domains, enhances ARMH aspect ratios from 0.1 to 0.8 without reducing manufacturing time, and maintains processing accuracy even with laser focus shifts, thereby addressing inconsistencies in large-area processing. As a proof of concept, approximately 7 billion ARMHs are fabricated on a 100-mm-diameter zinc sulfide (ZnS) window at a rate of 20 000 holes per second using LOFM technology assisted by machine learning. The fabricated DBAR ZnS window exhibits ultra-broadband (3.5–14 μm), high transmittance (91.1%), wide-angle transmission, wear-resistant, and self-cleaning, making it suitable for environments with multiple interference factors. Dual-band imaging applications demonstrate the significant advantages of DBAR windows in target recognition, multi-scenario robustness, and information acquisition.