Fig. 1. Evolution of ultrafast science and electronics^[11]

Fig. 2. Schematic diagram of ASOPS to detect reflectivity of sample^[14]

Fig. 3. Schematic diagrams of ASOPS system and its application^[28]

Fig. 4. Structure of femtosecond system with locked repetition rate^[33]

Fig. 5. Locking scheme where one laser is locked on the repetition rate difference of another freely operated laser^[16]

Fig. 6. Setup of ASOPS system^[34]

Fig. 7. Timing diagrams illustrating ECOPS principle^[63]

Fig. 8. Experimental setup for the cross-correlation measurement based on OSCAT^[22]

Fig. 9. Experimental diagram of AD-ASOPS^[27]

Fig. 10. Experimental diagram of PHIRE^[66]