Fig. 1. System schematic diagram of dual elastic differential frequency modulation

Fig. 2. Physical image of dual elastic differential frequency modulation

Fig. 3. Relationship between Bessel series and phase modulation amplitude

Fig. 4. Differential frequency modulation signal

Fig. 5. No sample measurement results

Fig. 6. Physical image of spectral ellipsometer (ESS01)

Fig. 7. Optical carrier signal after loading ellipsometric parameter information

Fig. 8. Sample test results