Toulouse Andrea, Drozella Johannes, Motzfeld Pascal, Fahrbach Nils, Aslani Valese, Thiele Simon, Giessen Harald, Herkommer Alois M
Opt Express. 2022 Jan 17;30(2):707-720. doi: 10.1364/OE.439963.
Simultaneous realization of ultra-large field of view (FOV), large lateral image size, and a small form factor is one of the challenges in imaging lens design and fabrication. All combined this yields an extensive flow of information while conserving ease of integration where space is limited. Here, we present concepts, correction methods and realizations towards freeform multi-aperture wide-angle cameras fabricated by femtosecond direct laser writing (fsDLW). The 3D printing process gives us the design freedom to create 180° × 360° cameras with a flat form factor in the micrometer range by splitting the FOV into several apertures. Highly tilted and decentered non-rotational lens shapes as well as catadioptric elements are used in the optical design to map the FOV onto a flat surface in a Scheimpflug manner. We present methods to measure and correct freeform surfaces with up to 180° surface normals by confocal measurements, and iterative fabrication via fsDLW. Finally, approaches for digital distortion correction and image stitching are demonstrated and two realizations of freeform multi-aperture wide-angle cameras are presented.
同时实现超大视场（FOV）、大尺寸横向图像以及小尺寸外形是成像镜头设计与制造中的挑战之一。所有这些因素结合在一起，在有限空间内实现易于集成的同时，产生了大量的信息流。在此，我们介绍了关于通过飞秒直接激光写入（fsDLW）制造的自由形式多孔径广角相机的概念、校正方法及实现方式。3D打印工艺赋予我们设计自由度，通过将视场分割为多个孔径，制造出具有微米级扁平外形的180°×360°相机。在光学设计中使用高度倾斜和偏心的非旋转透镜形状以及折反射元件，以倾斜校正方式将视场映射到平面上。我们提出了通过共焦测量来测量和校正具有高达180°表面法线的自由曲面的方法，以及通过fsDLW进行迭代制造的方法。最后，展示了数字畸变校正和图像拼接的方法，并介绍了自由形式多孔径广角相机的两种实现方式。
