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FSI system, one of the most promising optical surface measurement techniques, generally results in superior optical
performance comparing with other 3-dimensional measuring methods as its hardware structure is fixed in operation and
only the light frequency is scanned in a specific spectral band without vertical scanning of the target surface or the
objective lens. FSI system collects a set of images of interference fringe by changing the frequency of light source. After
that, it transforms intensity data of acquired image into frequency information, and calculates the height profile of target
objects with the help of frequency analysis based on FFT. However, it still suffers from optical noise from target surface
and relatively long processing time due to the number of images acquired in frequency scanning phase. First, a
polarization-based frequency scanning interferometry (PFSI) is proposed for optical noise robustness. It consists of
tunable laser for light source, λ/4 plate in front of reference mirror, λ/4 plate in front of target object, polarizing beam
splitter, polarizer in front of image sensor, polarizer in front of the fiber coupled light source, λ/2 plate between PBS and
polarizer of the light source. Using the proposed system, we can solve the problem low contrast of acquired fringe image
by using polarization technique. Also, we can control light distribution of object beam and reference beam. Second, the
signal processing acceleration method is proposed for PFSI, based on parallel processing architecture, which consists of
parallel processing hardware and software such as GPU (Graphic Processing Unit) and CUDA (Compute Unified Device
Architecture). As a result, the processing time reaches into tact time level of real-time processing. Finally, the proposed
system is evaluated in terms of accuracy and processing speed through a series of experiment and the obtained results
show the effectiveness of the proposed system and method.
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