Bioinspired fabrication of high-quality 3D artificial compound eyes by voxel-modulation femtosecond laser writing for distortion-free wide-field-of-view imaging

The small field-of-view (FOV) limits the range of vision in various detecting/imaging devices from biological microscopes to commercial cameras and military radar. To date, imaging with FOV over 90° has been realized with fish-eye lenses, catadioptric lens, and rotating cameras. However, these devices suffer from inherent imaging distortion and require multiple bulky elements. Inspired by compound eyes found in nature, here a small-size (84 μm), distortion-free, wide-FOV imaging system is presented via an advanced 3D artificial eye architecture. The 3D artificial eye structure is accomplished by exploiting an effective optical strategy - high-speed voxel-modulation laser scanning (HVLS). The eye features a hexagonal shape, high fill factor (FF) (100%), large numerical aperture (NA) (0.4), ultralow surface roughness (2.5 nm) and aspherical profile, which provides high uniformity optics (error < ±6%) and constant resolution (FWHM = 1.7 ± 0.1 μm) in all directions. Quantitative measurement shows the eye reduces imaging distortion by two/three times under 30°/45° incidence, compared with a single lens. The distortion-free FOV can be controlled from 30° to 90°.