Fig. 1. Schematic of white light interferometer imaging

Fig. 2. White light interference signal under illumination of white light LED. (a) Frequency-spectrum of interference signal; (b) white light interference signal

Fig. 3. White light interference signal and envelope curves of signals in different frequency bands

Fig. 4. Frequency-spectrum parameters and surface roughness under different energy ratios. (a) Relationship between wavenumber interval and energy ratio; (b) relationship between surface arithmetic mean height and energy ratio

Fig. 5. Relationship between cost function value and energy ratio

Fig. 6. Surface measurement results of silver mirror. (a)(b) Twice repeated measurements of the same area; (c) profile of two measurements at Y=174 µm; (d) deviation curve between the average value and the profile at Y=174 µm

Fig. 7. Step structure measurement result. (a) Three-dimensional topography of step structure; (b) profile of step structure at Y=174 µm