Microscopic imaging of non-repetitive dynamic scenes at 5 THz frame rates by time and spatial frequency multiplexing

TL;DR

This paper introduces a novel single-shot ultrafast microscopy technique capable of capturing over a dozen frames at 5 THz frame rates, significantly advancing the visualization of non-repetitive dynamic scenes.

Contribution

The authors developed a scalable ultrafast microscopy method combining spatial light modulation and custom echelon optics to record 14 frames simultaneously at unprecedented temporal resolution.

Findings

Captured 14 temporal snapshots in a single shot, the highest to date.

Achieved a frame rate of 5 THz, enabling ultrafast imaging of non-repetitive scenes.

Demonstrated high scalability in the number of frames and temporal resolution.

Abstract

Femtosecond-scale ultrafast imaging is an essential tool for visualizing ultrafast dynamics in molecular biology, physical chemistry, atomic physics, and fluid dynamics. Pump-probe imaging and a streak camera are the most widely used techniques, but they are either demanding the repetitions of the same scene or sacrificing the number of imaging dimensions. Many interesting single-shot ultrafast imaging techniques have been developed in recent years for recording non-repetitive dynamic scenes. Nevertheless, there are still weaknesses in the number of frames, the number of image pixels, or spatial/temporal resolution. Here, we present a single-shot ultrafast microscopy that can capture more than a dozen frames at a time with the frame rate of 5 THz. We combine a spatial light modulator and a custom-made echelon for efficiently generating a large number of reference pulses with designed time delays and propagation angles. The single-shot recording of the interference image between these reference pulses with a sample pulse allows us to retrieve the stroboscopic images of the dynamic scene at the timing of the reference pulses. We demonstrated the recording of 14 temporal snapshots at a time, which is the largest to date, with the optimal temporal resolution set by the laser output pulse. Our ultrafast microscopy is highly scalable in the number of frames and temporal resolutions, and this will have profound impacts on uncovering the interesting spatio-temporal dynamics yet to be explored.