Fig. 1. Short time, atomic time, electronic time, and nuclear time

Fig. 2. Correspondence among motion, energy, and time scale in the microcosmic world^［2］

Fig. 3. In flight light pulse experiment recorded by holographic coherent shutter^[26-29]. (a) Experimental principle (L represents picosecond laser, A represents small aperture diaphragm, O represents diffuser plate, and H represents holographic recording medium); (b) schematic of experimental lightpath (O represents diffuse reflection object and M represents mirror); (c) recorded propagation process of spherical wave and reflected wave

Fig. 4. Schematic of a bond-breaking process of ICN and the time-delay between adjacent two pumpings is 10 fs in the multi-pumping-detection^[35]

Fig. 5. Original femtosecond holography^[66-67]

Fig. 6. Frequency-domain hologram (up) and its system diagram (down) of plasma wake-field recorded by FDH^[10,70]

Fig. 7. Schematic of experimental setup of SSFDH

Fig. 8. Schematic of CUP system and tube streak camera^[48]

Fig. 9. Schematic of FRAME setup^[77]

Fig. 10. Schematic of optical system of FISI^[52]. (a) 3D model of FISI system, including the frequency domains FD1 and FD2, the lenses L1 and L2 of 4f system, the spatial plane (SD), the image plane (IP), and the sub-lens in lens array (LA); (b) lightpath diagram of FISI system; (c) isometric and front view of framing structure

Fig. 11. Schematic of STAMP^[50]

Fig. 12. Schematic of microscopic SF-STAMP system for observation of ultrafast laser ablation dynamics^[80]

Fig. 13. OPR system^[53-54]. (a) Schematic of OPR: (a1) demonstration of sampling theory and Fourier reconstruction algorithm; (a2) operating principle; (a3) raster framing camera (C—collimating lens, G—grating, FL—Fourier lens). (b) Experimental setup of OPR: (b1) ultrafast imaging in single-shot (WP—wedge plate, HWP—half wave plate, G1 and G2—gratings, DL—delay line, MO—microscope objective); (b2) raw spectrally dispersed raster of probe pulse without an object; (b3) details in the yellow dotted box in Fig. 13(a2); (b4) sub-bandwidth raster of a probe pulse

Fig. 14. MOPA system (WS—wavelength separator, SHG—second harmonic generator, NCOPA—non-collinear optical parametric amplifier, BSG—beam splitter group, COS—confocal optical system)^［88］

Fig. 15. Comparison among recent main imaging techniques of atomic time scale