Fig. 1. Schematic diagram of double-elastic ellipsometry measurement system

Fig. 2. Circuit diagram of dual-phase lock-in amplification

Fig. 3. Structure diagram of downsampling

Fig. 4. Structure diagram of first-order CIC filter

Fig. 5. CIC filter designed by Matlab

Fig. 6. FPGA simulation of CIC filter

Fig. 7. FIR filter spectrum generated by Matlab

Fig. 8. FPGA simulation of FIR filter

Fig. 9. Physical image of double-elastic ellipsometry system

Fig. 10. ψ and Δ without sample

Fig. 11. Sample measurement