Spatiotemporal shearing-based ultrafast framing photography for high performance transient imaging

Framing photography provides a high temporal resolution and minimizes crosstalk between adjacent frames, making it an indispensable tool for recording ultrafast phenomena. To date, various ultrafast framing photography techniques have been developed. However, simultaneously achieving large sequence depth, high image quality, ultrashort exposure time, and flexible frame interval remains a significant challenge. Herein, we present a spatiotemporal shearing-based ultrafast framing photography, termed STS-UFP, designed to address this challenge. STS-UFP employs an adjustable ultrashort laser pulse train with a spectrum shuttle to illuminate the dynamic scenes for extracting the transient information and records discrete frames using a streak camera via spatiotemporal shearing. Based on its unique design, STS-UFP achieves high-quality ultrafast imaging with a sequence depth of up to 16 frames and frame intervals ranging from hundreds of picoseconds to nanoseconds, while maintaining an extremely short (picosecond) exposure time. The exceptional performance of STS-UFP is demonstrated through experimental observations of femtosecond laser-induced plasma and shockwave in water, femtosecond laser ablation in biological tissue, and femtosecond laser-induced shockwave on a silicon surface. Given its remarkable imaging capabilities, STS-UFP serves as a powerful tool for precisely observing ultrafast dynamics and holds significant potential for advancing studies of ultrafast phenomena.