Surface profile measurement in white-light scanning interferometry using a three-chip color CCD

Area of Science:

• Optical Metrology
• Surface Profilometry
• Interferometry

Background:

• White-light scanning interferometry (WLSI) is valuable for measuring surfaces with discontinuities.
• Conventional WLSI uses monochrome CCD cameras, discarding color information from interferograms.
• This loss of color data limits the precision and detail achievable in surface profile measurements.

Purpose of the Study:

• To propose a novel WLSI method utilizing color information for enhanced surface profile measurement.
• To investigate the use of phase information from red-green-blue (RGB) color channels.
• To demonstrate the effectiveness of the new method using a three-chip color CCD camera.

Main Methods:

• Acquisition of interferograms using a three-chip color CCD camera in WLSI.
• Extraction of phase values from individual RGB color channels.
• Application of the windowed Fourier transform algorithm for phase analysis.

Main Results:

• The proposed method successfully extracts phase information from different color channels.
• Simulation results validate the feasibility of the RGB channel phase extraction technique.
• Experimental data confirm the practical applicability and accuracy of the novel WLSI approach.

Conclusions:

• The novel WLSI method effectively utilizes color channel phase information for precise surface profiling.
• This approach overcomes the limitations of traditional methods by preserving and analyzing color data.
• The technique offers a promising advancement for measuring complex microstructures and discontinuous surfaces.