Suppression of ghost artifacts in polarization-sensitive optical coherence tomography

Polarization-sensitive optical coherence tomography (PS-OCT) can provide quantifiable polarization parameters to assess the physiological and pathological states. The utilization of polarization-maintaining fiber (PMF) further improves the stability and flexibility of PS-OCT, expanding the clinical application of PS-OCT. However, PMFbased PS-OCT suffers from serious polarization artifacts due to polarization cross-coupling, especially the ghost artifact. The complex manifestation of the ghost artifact and the lack of an established theory for its generation seriously limit the development of effective artifact suppression. In this study, we derived the theory of the ghost artifact generation and obtained the quantitative relationship between the intensity of the ghost artifact and the sample. Besides, by comparing imaging results containing artifacts with those from an artifact- free bulk-based PS-OCT system, it was demonstrated that ghost artifacts not only introduce pseudo structures but also cause errors in polarization parameters. Based on our derived theory, a novel artifact suppression method combining pre-measurement with actual measurement was proposed. The images before and after artifact removal showed that the proposed method effectively suppressed ghost artifacts and corrected polarization errors, with only a negligible increase in computation time (approximately 10% of the original calculation time). This study improved the reliability and accuracy of PS-OCT, offering promising theoretical value and clinical application potential.