She Alan, Zhang Shuyan, Shian Samuel, Clarke David R, Capasso Federico
Opt Express. 2018 Jan 22;26(2):1573-1585. doi: 10.1364/OE.26.001573.
Optical components, such as lenses, have traditionally been made in the bulk form by shaping glass or other transparent materials. Recent advances in metasurfaces provide a new basis for recasting optical components into thin, planar elements, having similar or better performance using arrays of subwavelength-spaced optical phase-shifters. The technology required to mass produce them dates back to the mid-1990s, when the feature sizes of semiconductor manufacturing became considerably denser than the wavelength of light, advancing in stride with Moore's law. This provides the possibility of unifying two industries: semiconductor manufacturing and lens-making, whereby the same technology used to make computer chips is used to make optical components, such as lenses, based on metasurfaces. Using a scalable metasurface layout compression algorithm that exponentially reduces design file sizes (by 3 orders of magnitude for a centimeter diameter lens) and stepper photolithography, we show the design and fabrication of metasurface lenses (metalenses) with extremely large areas, up to centimeters in diameter and beyond. Using a single two-centimeter diameter near-infrared metalens less than a micron thick fabricated in this way, we experimentally implement the ideal thin lens equation, while demonstrating high-quality imaging and diffraction-limited focusing.
诸如透镜之类的光学元件传统上是通过对玻璃或其他透明材料进行成型来制成块状的。超表面技术的最新进展为将光学元件重塑为薄的平面元件提供了新的基础,这些平面元件使用亚波长间隔的光学相移器阵列具有相似或更好的性能。大规模生产它们所需的技术可以追溯到20世纪90年代中期,当时半导体制造的特征尺寸比光的波长密集得多,并随着摩尔定律同步发展。这为统一两个行业提供了可能性:半导体制造和透镜制造,即用于制造计算机芯片的相同技术被用于制造基于超表面的光学元件,如透镜。使用一种可扩展的超表面布局压缩算法,该算法能以指数方式减小设计文件大小(对于直径为一厘米的透镜可减小3个数量级)以及步进光刻技术,我们展示了直径达厘米及以上的超大尺寸超表面透镜(金属透镜)的设计与制造。使用以此方式制造的单个直径为两厘米、厚度小于一微米的近红外金属透镜,我们通过实验实现了理想的薄透镜方程,同时展示了高质量成像和衍射极限聚焦。