State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instrument, Tsinghua University, Beijing, 100084, China.
Nat Commun. 2023 Feb 23;14(1):1035. doi: 10.1038/s41467-023-36812-6.
It is a grand challenge for an imaging system to simultaneously obtain multi-dimensional light field information, such as depth and polarization, of a scene for the accurate perception of the physical world. However, such a task would conventionally require bulky optical components, time-domain multiplexing, and active laser illumination. Here, we experimentally demonstrate a compact monocular camera equipped with a single-layer metalens that can capture a 4D image, including 2D all-in-focus intensity, depth, and polarization of a target scene in a single shot under ambient illumination conditions. The metalens is optimized to have a conjugate pair of polarization-decoupled rotating single-helix point-spread functions that are strongly dependent on the depth of the target object. Combined with a straightforward, physically interpretable image retrieval algorithm, the camera can simultaneously perform high-accuracy depth sensing and high-fidelity polarization imaging over an extended depth of field for both static and dynamic scenes in both indoor and outdoor environments. Such a compact multi-dimensional imaging system could enable new applications in diverse areas ranging from machine vision to microscopy.
对于成像系统来说，同时获取场景的多维光场信息（如深度和偏振），从而准确感知物理世界，是一项巨大的挑战。然而，这样的任务通常需要体积庞大的光学元件、时域复用和主动激光照明。在这里，我们实验演示了一种配备单层超构透镜的紧凑型单目相机，它可以在环境光照条件下，单次拍摄捕获包括目标场景的二维全聚焦强度、深度和偏振在内的 4D 图像。该超构透镜经过优化，具有一对共轭的偏振解耦旋转单螺旋点扩散函数，它们强烈依赖于目标物体的深度。结合一种简单、具有物理可解释性的图像检索算法，该相机可以在室内和室外的静态和动态场景中，在扩展景深范围内，同时进行高精度深度感应和高保真偏振成像。这种紧凑型多维成像系统可以在从机器视觉到显微镜等多个领域中实现新的应用。
