Rapid Engraving of Artificial Compound Eyes from Curved Sapphire Substrate

With high thermal and mechanical stability, glass artificial compound eyes have great potential applications in wide field-of-view (FOV) imaging and fast detection. However, the rapid fabrication of large-area, high integration, uniform, and well-designed three-dimensional (3D) glass compound eyes is still a great challenge. Here, a dry-etching-assisted femtosecond laser machining (DE-FsLM) technology is proposed for fabrication of cm-sized concave compound eye from a curved sapphire substrate, with which the fabrication efficiency can be improved by over two orders of magnitude compared with direct laser ablation. With high hardness and thermal stabilities, the sapphire concave compound eyes can be used as high-temperature and hard-casting templates for the replication of convex compound eyes on K9 glass. The replicated cm(2)-size all-glass compound eye consists of a spherical macrolens (1 cm diameter and 2.3 mm height) and over 190 000 close-packed ommatidia (approximate to 20 mu m diameter and 1.5 mu m height). The compound eyes exhibit excellent optical properties with wide FOV (up to 90 degrees) imaging and focusing. These results indicate that the DE-FsLM and casting replication technology will open new opportunities in micro-/nanofabrication of hard materials.