| 摘要: | 像差是所有鏡頭都會遇到的問題，過去人們習慣使用非球面鏡片來解決這個問題，但這種透鏡的製作過於繁瑣且成本較高，因此球面透鏡成為新的解決方案，雖然球面透鏡相比於非球面鏡片更容易製作且成本更低，但是如果要實現高品質成像通常需要多片透鏡的組合，這使鏡頭成像品質提升之餘也讓鏡頭組變得更大更厚重，這也是市面上多數鏡頭所面臨到的共同問題，因此各界積極尋求各種方法來解決，此時超穎透鏡的興起無疑成為其中一個可行的解決方案，它提供了另一種消除像差的選擇，旨在使用較少的透鏡來完成相同的成像效果。在這篇論文中，我們以超穎透鏡為基礎提出了一個由超穎校正器和庫克三透鏡所組成的相機鏡頭系統。
在這裡主要可以分成三部分，分別是模擬、製程和量測。首先，我們使用商業軟體ZEMAX來計算超穎校正器的理想相位分佈，並利用Matlab對該相位進行進一步確認及優化，完成相位設計後，我們根據所使用的材料建立資料庫，並依據資料庫填入不同的圓柱，以提供不同的相位調製，接下來我們根據模擬出的相位設計出超穎校正器的結構圖，並使用電子束微影技術(electron beam lithography)進行曝光，最後利用量測來觀察超穎校正器對成像的影響。
我們可以先從模擬結果得知加上超穎校正器後庫克三透鏡的光斑尺寸可以從17.658m大幅縮小到1.106 m，而且在加上超穎校正器後，庫克三透鏡的空間頻率提高許多且相當接近繞射極限，不只在模擬方面有此結果，量測上也顯示出一樣的效果，不論是PSF乃至MTF都能看出與模擬上近似的效果，藉由這些分析都能再次證明超穎校正器確實可以消除大部分的球差。
;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. |
