Fig. 1. Flow chart of SVMD-HD filtering algorithm

Fig. 2. Physical image of experimental setup

Fig. 3. White light interference signal diagram.

Fig. 4. IMFs obtained by SVMD

Fig. 5. Hausdorff distance between each modal component and original signal as well as threshold

Fig. 6. Results of signal filtering in Fig.4 ( b ) by using SVMD-HD

Fig. 7. Surface measuring results with step height of 10 μm by traditional algorithm

Fig. 8. Surface measurement results of standard steps with height of 10 μm

Fig. 9. Measurement results of step devices with heights of 500 nm and 1 200 nm