Ultrafast single-shot burst imaging in a few-nanosecond window using a spectrally sweeping laser pulse train

To capture ultrafast non-repeatable phenomena, we had developed two methods of single-shot ultrafast two-dimensional (2D)- imaging of sequentially timed all-optical mapping photography (STAMP) [1] and STAMP utilizing spectral filtering (SF-STAMP) [2, 3]. In these STAMP schemes, spectral images measured by a linearly frequency-chirped laser pulse corresponds to time-resolved snapshots. So far, we achieved single-shot burst imaging of ultrafast phenomena in picosecond time windows with sub-picosecond temporal resolutions. However, it is not straightforward to extend the time window beyond 10 ps by a conventional method to chirp the probe laser pulse using material dispersion. Currently, we applied a new scheme of free-space angular-chirp-enhanced delay (FACED) [4] composed of a tilted pair of mirrors to SF-STAMP and achieved a sub-ns time window [5]. In this work, we generated spectrally sweeping burst pulses with a 300-ps-pulse interval by FACED, and captured single-shot ultrafast 2D-burst images with a few-nanosecond time window. Furthermore we combined a 1-kfps fast camera. Repetitive laser ablation was captured with 10-frame, 300-ps interval images at every 1 ms.