Fast Pump-Probe Microscopy Imaging with Asynchronous Optical Sampling
Ajinkya Shingote, Naomi Ross, Janak Bhandari, Bikram Ghosh, Vadim Trepalin, Debasish Panda, Svetlana Neretina, Som Subhra Guria, Petr Stepanov, Kenji Watanabe, Takashi Taniguchi, Gregory V. HartlandAbstract
Asynchronous optical sampling (ASOPS) allows rapid collection of transient absorption/reflection data over wide time scales with a high dynamic range in both time and signal magnitude. In this paper, a method for recording transient images using ASOPS is presented based on time-gated integration of the transient signal. This technique allows diffraction-limited pump-probe microscopy images to be rapidly collected at precise, user-specified time delays, with approximately 15 picoseconds time resolution. Results are presented for the excited-state dynamics in multilayered WSe2 flakes, charge-carrier diffusion in a silicon wafer, and images of Au nanoparticle arrays that demonstrate the spatial/temporal resolution and sensitivity of the technique. Potential applications and the ultimate time resolution that can be achieved are also discussed.