| dc.description.abstract | Aberrations are common issues encountered in all lenses. Historically, aspheric lenses have been used to address this problem. However, the fabrication of aspheric lenses is complex and costly. Consequently, spherical lenses have emerged as a new solution. Although spherical lenses are easier and less expensive to manufacture compared to aspheric lenses, achieving high-quality imaging typically requires a combination of multiple lenses. While this approach enhances image quality, it also results in larger and heavier lens assemblies, which is a common challenge for most lenses on the market. This has driven the industry to actively seek various solutions. Among these, the advent of metalenses stands out as one of the potential solutions. Metalenses offer an alternative approach to eliminate aberrations, aiming to achieve the same imaging quality with fewer lenses.
In this paper, we propose a camera lens system based on a meta-corrector integrated with a Cooke triplet. This study can be divided into three main parts: simulation, fabrication, and measurement. Initially, we used the commercial software ZEMAX to calculate the ideal phase distribution for the meta-corrector, and further verified and optimized this phase using Matlab. After completing the phase design, we constructed a database based on the materials used and populated it with various cylindrical elements to provide different phase modulations. Subsequently, we designed the photomask according to the simulated phase and employed electron beam lithography (E-BEAM) technology for the fabrication process. Finally, we observed the impact of the meta-corrector on imaging through measurements.
From the simulation results, we observed that incorporating the meta-corrector significantly reduced the spot size of the Cooke triplet from 17.658 m to 1.106 m. Additionally, the spatial frequency of the Cooke triplet increased considerably with the meta-corrector, approaching the diffraction limit. This effect was not only observed in simulations but also confirmed through measurements. Both the point spread function (PSF) and the modulation transfer function (MTF) demonstrated effects similar to those predicted by simulations. These analyses reaffirm that the meta-corrector can indeed eliminate most of the spherical aberrations. | en_US |