Lai Yingming, Shang Ruibo, Côté Christian-Yves, Liu Xianglei, Laramée Antoine, Légaré François, Luke Geoffrey P, Liang Jinyang
Opt Lett. 2021 Apr 1;46(7):1788-1791. doi: 10.1364/OL.420737.
Existing streak-camera-based two-dimensional (2D) ultrafast imaging techniques are limited by long acquisition time, the trade-off between spatial and temporal resolutions, and a reduced field of view. They also require additional components, customization, or active illumination. Here we develop compressed ultrafast tomographic imaging (CUTI), which passively records 2D transient events with a standard streak camera. By grafting the concept of computed tomography to the spatiotemporal domain, the operations of temporal shearing and spatiotemporal integration in a streak camera's data acquisition can be equivalently expressed as the spatiotemporal projection of an (,,) datacube from a certain angle. Aided by a new, to the best of our knowledge, compressed-sensing reconstruction algorithm, the 2D transient event can be accurately recovered in a few measurements. CUTI is exhibited as a new imaging mode universally adaptable to most streak cameras. Implemented in an image-converter streak camera, CUTI captures the sequential arrival of two spatially modulated ultrashort ultraviolet laser pulses at 0.5 trillion frames per second. Applied to a rotating-mirror streak camera, CUTI records an amination of fast-bouncing balls at 5,000 frames per second.
现有的基于条纹相机的二维超快成像技术受到采集时间长、空间分辨率与时间分辨率之间的权衡以及视场减小的限制。它们还需要额外的组件、定制或主动照明。在此，我们开发了压缩超快层析成像（CUTI），它使用标准条纹相机被动记录二维瞬态事件。通过将计算机断层扫描的概念移植到时空域，条纹相机数据采集中的时间剪切和时空积分操作可以等效地表示为从某个角度对一个（,,）数据立方体的时空投影。借助一种据我们所知全新的压缩感知重建算法，二维瞬态事件可以在几次测量中被准确恢复。CUTI展现为一种普遍适用于大多数条纹相机的新成像模式。在变像管条纹相机中实现时，CUTI以每秒5万亿帧的速度捕捉两个空间调制的超短紫外激光脉冲的相继到达。应用于转镜条纹相机时，CUTI以每秒5000帧的速度记录快速弹跳球的动画。
