Fringe-Distortion-Correction for Polarized Low-Coherence Interferometry With Phosphor-Based LED

An interferogram distortion correction method is proposed for polarized low-coherence interferometry with the phosphor-based LED. A mathematical model of the interference fringes with distortion was established to analyze the distortion influence caused by the combined influence of the dual Gaussian-like peak spectral phosphor-based LED and the location-related birefringence dispersion of the polarization low coherence interference system. With the distortion model, the proposed method corrected the mismatch of the envelope peak and the phase peak based on the central wavenumber of single Gaussian-like peak spectrum, and the interference fringes envelope offset of dual Gaussian-like peak spectrum. A pressure experiment was carried out to verify the feasibility of the proposed method. According to the experiment result, the interferogram distortion was corrected effectively, the precision of demodulation was improved, and the demodulation error was less than 0.06 kPa in the pressure measurement range of 230 kPa. The interference fringes intensity was also increased by 10% compared to the original intensity.