论文标题
通过反向设计的平面镜头从可见光到长波红外波长成像
Imaging from the Visible to the Longwave Infrared wavelengths via an inverse-designed flat lens
论文作者
论文摘要
通常认为，在成像中校正色差需要光学元素。在这里，我们表明，通过允许图像平面中的相位是一个自由参数，可以使用单个衍射表面（即，平坦的镜片）校正极大带宽（VIS）到长波红外（LWIR）波长的焦距变化。具体而言，我们设计，制造和表征了厚度为10μm，直径〜1mm和焦距= 18mm的平坦的多级衍射透镜（MDL），在L =0.45μm（蓝色）至15μm（LWIR）的工作带宽上是恒定的。我们通过实验表征了由该MDL和适当的图像传感器组成的相机的点传播函数，畸变和成像性能。我们进一步使用模拟表明，即使在高数值孔径下，也可以实现这种极端的可观MDL（Na = 0.81）。通过大大增加操作带宽并消除了几种折射镜头，我们的方法可以使更薄，更轻，更简单的成像系统。
It is generally assumed that correcting chromatic aberrations in imaging requires optical elements. Here, we show that by allowing the phase in the image plane to be a free parameter, it is possible to correct chromatic variation of focal length over an extremely large bandwidth, from the visible (Vis) to the longwave infrared (LWIR) wavelengths using a single diffractive surface, i.e., a flat lens. Specifically, we designed, fabricated and characterized a flat, multi-level diffractive lens (MDL) with thickness £ 10μm, diameter ~1mm, and focal length = 18mm, which was constant over the operating bandwidth of l=0.45μm (blue) to 15μm (LWIR). We experimentally characterized the point-spread functions, aberrations and imaging performance of cameras comprised of this MDL and appropriate image sensors. We further show using simulations that such extreme achromatic MDLs can be achieved even at high numerical apertures (NA=0.81). By drastically increasing the operating bandwidth and eliminating several refractive lenses, our approach enables thinner, lighter and simpler imaging systems.
