Minimalist optical system for achromatic imaging within extended field of view based on monolithic integrated meta-axicon cluster

Achromatic metalenses face stringent aperture and numerical aperture (NA) constraints, which have become a key bottleneck in metasurface imaging. To this end, a novel achromatic imaging method was first proposed, utilizing the unique wideband consistency of diffracted Bessel spots combined with non-blind image restoration techniques. To address the off-axis aberration issue, off-axis achromatic meta-axicons with eccentric conical phases were further designed to convert oblique plane waves into wideband uniform off-axis Bessel beams. Ultimately, a single metasurface integrating 9 meta-axicons with different design field angles was developed, and a meta-camera was constructed accordingly. After image restoration, the meta-camera achieves achromatic imaging within a 10° stitched field of view (FOV), and an angular resolution close to that of near-diffraction-limit lens with the same aperture throughout the entire FOV. The core idea of achieving achromatic imaging based on natural dispersion laws in this study enables the wideband minimalist optical system based on metasurface to completely circumvent the aperture limitation, providing a highly valuable solution for large-aperture meta-camera design that can simultaneously accommodate wideband and off-axis FOV.