CAREER: A Single Shot Camera Capturing Ultrafast Dynamic Phenomena

这项研究的重点是开发超快成像的新方法。特别是，它将有助于超快光学和X射线相机的新发展，能够提供前所未有的空间和时间分辨率的分子电影。这将极大地推动超快光学科学在单分子成像、光-物质相互作用和惯性约束聚变方面的发展。该项目还包括一些教育活动，例如为本科生和研究生开发一个夏季/冬季光学短期课程，以及每年在国际和平研究所的实验室培训一名毕业生和两名本科生和/或当地高中生。这项研究还包括在个人和合作研究环境中为学生提供广泛的教育活动。传统的泵浦-探针法通常可以提供超快的时间分辨率成像，但它们大多适用于高度可重复性的事件。然而，如果事件到事件的重现性是不规则的，或者涉及到材料损坏、不可逆转的化学反应和/或结构相变，则单次探测是必要的。这里的项目是开发一种单镜头相机，能够捕捉超快动态图像，同时在单镜头中记录空间(2维)和时间演变。这种相机可以以每秒50万亿帧的帧速率拍摄图像，单次拍摄3~60帧。在这里，使能技术包括超宽带光谱产生、超快光脉冲整形和单次激发高光谱成像。这种相机在材料表征、生物医学成像、生物传感器、光学和等离子体诊断等方面具有潜在的应用前景。特别是，它在X射线自由电子激光中的应用将导致超短电子束成像和表征。

This research is focused on developing new methodologies for ultrafast imaging. In particular, it will contribute to a new development of ultrafast optical and X-ray cameras capable of providing molecular movies with unprecedented spatial and temporal resolution. This will greatly advance ultrafast optical science in single-molecule imaging, light-matter interaction, and inertial confinement fusion. The project also includes educational activities such as developing a summer/winter short course in optical science for undergraduate and graduate students, as well as training one graduate and two undergraduate and/or local high school students per year in the PI's laboratory. The research also includes extensive educational activities for students in individual and collaborative research settings.Conventional pump-probe methods can routinely provide ultrafast time-resolved imaging, but they mostly work for highly repeatable events. However, if event-to-event reproducibility is irregular or involves material damage, irreversible chemical reactions, and/or structural phase transition, single-shot detection is a necessity. The project here is to develop a single-shot camera capable of capturing ultrafast dynamic images, simultaneously recording spatial (2-dimensional) and temporal evolutions in a single-shot. Such a camera can capture images at a frame rate of ~50 trillion frames per second, recording 3 ~ 60 frames in a single-shot. Here, the enabling technologies include ultra-broadband spectrum generation, ultrafast optical pulse shaping, and single-shot hyperspectral imaging. This kind of camera can be potentially used in material characterization, biomedical imaging, bio-sensors, and optical and plasma diagnostics. In particular, its application in X-ray free electron lasers will lead to ultrashort electron beam imaging and characterization.