Single-shot 25-frame burst imaging of ultrafast phase transition of Ge₂Sb₂Te5 with a sub-picosecond resolution

We captured ultrafast two-dimensional (2D)-burst images of the crystalline-to-amorphous phase transition of Ge₂Sb₂Te5. These transitions were induced by a femtosecond laser pulse, and the images, with a sub-picosecond temporal resolution, were acquired on a single-shot basis through the change in local optical transmittance. We employed a 2D-burst imaging method of sequentially timed all-optical mapping photography utilizing spectral filtering (SF-STAMP). The SF-STAMP system consists of a 25-beam-generating diffractive optical element, a band-pass filter, and two Fourier transform lenses. We used a frequency-chirped broadband pulse and achieved 25-frame burst imaging with an interval of 133 fs in a singleshot time window of 3.2 ps.