近日，日本东京大学的Kuniaki Konishi及其研究团队取得一项新进展。他们通过i线步进机，实现了全彩色光刻胶制备的光学菲涅耳波带板平面透镜。相关研究成果已于2025年1月16日在国际知名学术期刊《光：科学与应用》上发表。

本研究提出一种简化方法，用于制造可见光菲涅耳波带板（FZP）平面透镜（一种衍射光学元件），该方法采用i线步进机和一种特殊的光刻胶（彩色光刻胶），仅需涂胶、曝光和显影，无需蚀刻或其他后处理步骤。研究人员使用传统光刻设备在8英寸石英玻璃晶片上制造了可见光FZP透镜图案，并实现了将550纳米光聚焦至1.1微米直径的光斑，聚焦效率为7.2%。数值模拟结果与实验结果高度一致，验证了本方法的高精度和设计性。

该研究的透镜还能对特征尺寸小至1.1微米的物体进行成像，展示了其在成像领域的实际应用潜力。本方法是一种成本效益高、操作简便且可扩展的解决方案，适用于可见光区域工作的平面透镜及其他光学元件的大规模生产。它促进了先进微型光学系统的开发，以满足现代技术的需求，为光学元件制造领域做出了重要贡献。

据悉，光操纵与控制在当代多种技术中至关重要，随着这些技术的不断发展，对微型光学元件的需求日益增长。近年来，超表面和衍射光学元件等平面透镜技术因其有望大幅减小传统折射光学系统的厚度而备受关注。然而，这些技术的制造过程，尤其是针对可见光波长的制造，涉及高分辨率光刻和干法刻蚀等复杂且成本高昂的工序，从而限制了其广泛应用。

附：英文原文

Title: Optical Fresnel zone plate flat lenses made entirely of colored photoresist through an i-line stepper

Author: Yamada, Ryohei, Kishida, Hiroyuki, Takami, Tomohiro, Rittaporn, Itti, Matoba, Mizuho, Sakurai, Haruyuki, Konishi, Kuniaki

Issue&Volume: 2025-01-16

Abstract: Light manipulation and control are essential in various contemporary technologies, and as these technologies evolve, the demand for miniaturized optical components increases. Planar-lens technologies, such as metasurfaces and diffractive optical elements, have gained attention in recent years for their potential to dramatically reduce the thickness of traditional refractive optical systems. However, their fabrication, particularly for visible wavelengths, involves complex and costly processes, such as high-resolution lithography and dry-etching, which has limited their availability. In this study, we present a simplified method for fabricating visible Fresnel zone plate (FZP) planar lenses, a type of diffractive optical element, using an i-line stepper and a special photoresist (color resist) that only necessitates coating, exposure, and development, eliminating the need for etching or other post-processing steps. We fabricated visible FZP lens patterns using conventional photolithography equipment on 8-inch silica glass wafers, and demonstrated focusing of 550nm light to a diameter of 1.1μm with a focusing efficiency of 7.2%. Numerical simulations showed excellent agreement with experimental results, confirming the high precision and designability of our method. Our lenses were also able to image objects with features down to 1.1μm, showcasing their potential for practical applications in imaging. Our method is a cost-effective, simple, and scalable solution for mass production of planar lenses and other optical components operating in the visible region. It enables the development of advanced, miniaturized optical systems to meet modern technology demand, making it a valuable contribution to optical component manufacturing.

DOI: 10.1038/s41377-024-01725-6

Source: https://www.nature.com/articles/s41377-024-01725-6