Fabrication of bifocal curved compound eyes for large-DOF and wide-FOV imaging via femtosecond laser 3D printing

Miniature imaging systems are pivotal in applications such as medical endoscopes , micro-robotics, virtual reality, and military reconnaissance . Nonetheless, achieving both an extended depth of field and a broad field of view in compact imaging devices remains a significant challenge. In nature, the sub-eye of trilobite compound eye exhibits a remarkable structure that focuses incoming light onto two distinct focal planes , enabling the simultaneous detection of both proximate and distant objects. Drawing inspiration from trilobite compound eye, this study introduces an innovative bioinspired design featuring a bifocal curved compound eye, offering an enhanced depth of focus and an expansive field of view. Meanwhile, the focal lengths of sub-lenses with varying orientations are meticulously designed to ensure convergence on a common imaging plane, thereby addressing the challenge of detector reception. The compound lens is manufactured through femtosecond laser 3D printing technology to achieve high-fidelity profiles that match the design. Experimental results demonstrate that the compound lens can concurrently capture images with a 90° field of view from near (<200 μm) to far (>10 cm) objects, without the need for mechanical zoom mechanisms. This breakthrough provides fresh perspectives for future applications in micro-vision technologies, including medical diagnostics and reconnaissance robotics.