A New Ultrafast Imaging Method Connects Dynamics Across Five Orders of Magnitude in Time in a Single Shot

The research team has developed a new ultrafast imaging method that changes the timing between frames to follow extremely fast phenomena over widely different timescales. The method, called logarithmic ultrafast photography, captured dynamics spanning approximately five orders of magnitude in time—from the 100-femtosecond range to 10 nanoseconds—in a single shot using 11 frames.

Conventional ultrafast imaging faces a trade-off: closely spaced frames can resolve rapid changes but cover only a short time window, while wider spacing extends the observation time but can miss the earliest dynamics. The research team addressed this problem by placing frames densely at early times and progressively farther apart at later times. To realize this flexible timing, the team developed an optical technique called band-resolved individual delay generation (BRIDGE), which independently controls the arrival time of light at different wavelengths.

Using the new method, the researchers observed laser-induced changes in glass and hydroxyapatite, a major component of bone and teeth. A single laser shot captured the sequence from the earliest plasma-related changes to later shock waves and material ejection. The images also revealed that the two materials developed distinctly different responses at later times.

By connecting processes that occur on very different timescales within the same event, the method could be particularly useful for studying phenomena that are difficult to reproduce exactly from one experiment to another. Potential applications include laser processing, material dynamics, biomedical research, plasma and shock-wave studies, and high-energy-density science.

Logarithmic ultrafast photography bridging dynamics across five orders of magnitude in time

Papers 
Journal: Optica
Title: Logarithmic ultrafast photography with band-resolved individual delay generation
Authors: Keitaro Shimada, Kohei Azuma, Jun Horiuchi, Dylan Thomas, Masato Ota, Keiichi Nakagawa
DOI: 10.1364/OPTICA.610944