Abstract
While the concept of focusing usually applies to the spatial domain, it is equally applicable to the time domain. Real-time imaging of temporal focusing of single ultrashort laser pulses is of great significance in exploring the physics of the space–time duality and finding diverse applications. The drastic changes in the width and intensity of an ultrashort laser pulse during temporal focusing impose a requirement for femtosecond-level exposure to capture the instantaneous light patterns generated in this exquisite phenomenon. Thus far, established ultrafast imaging techniques either struggle to reach the desired exposure time or require repeatable measurements. We have developed single-shot 10-trillion-frame-per-second compressed ultrafast photography (T-CUP), which passively captures dynamic events with 100-fs frame intervals in a single camera exposure. The synergy between compressed sensing and the Radon transformation empowers T-CUP to significantly reduce the number of projections needed for reconstructing a high-quality three-dimensional spatiotemporal datacube. As the only currently available real-time, passive imaging modality with a femtosecond exposure time, T-CUP was used to record the first-ever movie of non-repeatable temporal focusing of a single ultrashort laser pulse in a dynamic scattering medium. T-CUP’s unprecedented ability to clearly reveal the complex evolution in the shape, intensity, and width of a temporally focused pulse in a single measurement paves the way for single-shot characterization of ultrashort pulses, experimental investigation of nonlinear light-matter interactions, and real-time wavefront engineering for deep-tissue light focusing.
Highlights
The space–time duality in optics originates from the mathematical equivalence between paraxial diffraction and dispersive propagation[1]
To enable real-time, ultrafast, passive imaging of temporal focusing, here, we have developed single-shot trillion-frame-per-second compressed ultrafast photography (T-CUP), which can image non-repeatable transient events at a frame rate of up to 10 Tfps in a receiveonly fashion
The operation of T-CUP consists of data acquisition and image reconstruction (Fig. 1)
Summary
The space–time duality in optics originates from the mathematical equivalence between paraxial diffraction and dispersive propagation[1] This duality enables one to translate spatial-domain optical techniques to the temporal domain, which has fostered the development of powerful temporal imaging approaches, such as temporal microscopy, to characterize optical signals[2,3]. The nanometer-tomicrometer spatial scales of these transient events demand ultrafast imaging for blur-free observation [e.g., for imaging a light-speed event, an imaging speed of 1 trillion frames-per-second (Tfps) is required for a spatial resolution of 300 μm]15. Since these events are often self-luminescent, a passive (i.e., receive-only) detector is highly desired for direct recording
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
