School of Electronics and Information Engineering, Sichuan University, Chengdu, 610065, China.
Sci Rep. 2022 Nov 8;12(1):18996. doi: 10.1038/s41598-022-22103-5.
Wide field of view (FOV) images and magnified images can be taken simultaneously by dual-sensor imaging systems. Here, we propose an approach for creating a bifocal flat lens with different imaging characteristics of its two foci, which makes dual-sensor imaging systems more integrated and miniaturized. That is, two special parts of two different conventional ZP are extracted and then combine the two elements in a specific way. So that there are two foci with different characteristics along the optical axis, one is long focus with higher resolution, the other is short focus with long depth of focus (DOF). Under the proposed approach, a thin and light bifocal diffractive lens (BDL) with thickness of 0.6 μm is developed. The long and short focal lengths of the BDL are ~ 81 mm and ~ 27 mm, respectively, with a diameter of 6 mm. We experimentally demonstrate that the long focus of the BDL is capable of taking high-resolution magnified images, and its resolution is up to 21.90″. The short focus is able to take wide FOV with long DOF images, and two objects spread 2880 mm apart can be imaged clearly. The experiment results demonstrate that all of these metrics are better than those of a conventional refractive lens.
双传感器成像系统可以同时拍摄宽视场 (FOV) 图像和放大图像。在这里，我们提出了一种方法，可以创建具有两个焦点不同成像特性的双焦点平面透镜，从而使双传感器成像系统更加集成和小型化。也就是说，从两个不同的常规 ZP 中提取两个特殊部分，然后以特定的方式组合这两个元件。这样，在光轴上就有两个具有不同特性的焦点，一个是长焦距，分辨率更高，另一个是短焦距，景深更长。在提出的方法中，开发了一种厚度为 0.6 μm 的薄而轻的双焦点衍射透镜 (BDL)。BDL 的长焦距和短焦距分别约为 81mm 和 27mm，直径为 6mm。我们通过实验证明，BDL 的长焦距能够拍摄高分辨率的放大图像，其分辨率高达 21.90″。短焦距能够拍摄具有长景深的宽视场图像，并且可以清晰地对相距 2880mm 的两个物体进行成像。实验结果表明，所有这些指标都优于传统折射透镜。
